Friday, June 16, 2023

Music21 v9 released!

 Music21 v9 (June 2023) is the latest release of music21, a toolkit for computational music research.

Version 9 contains about 600 new commits and features from the version 8 release from September 2022. It is the latest and best release in the industry standard toolkit for doing music research and composition ("traditional" computation and AI/ML) with musical scores.

As a new Version X release, music21 gains a lot of its power with a few non-backwards compatible changes that make the system easier to use, faster, and more up to date. People using music21 in existing environments should read the change logs to make sure their systems work with it before upgrading.

A big change in music21 is that v9 is compatible with Python 3.10 and 3.11 only. The version 9 release will be updated to be compatible with at least Python 3.12 when it is released. Users on Python 3.8 and 3.9 should stick with v8 and those on older versions should look at the README to see what version will be installed for their systems.

See for a list of all major changes.

There are improvements to Corpus, Typing, DOCS!, RomanText and related formats, RomanNumerals and ChordSymbols, MusicXML (tempo, RN, measures, fingering), Speed improvements throughout, Braille, Converter, Frozen Objects, expanding subconverter, Ornaments, Spanners, Percussion, MIDI import, ABC, and stream tools, along with tons of bug fixes, and a few incompatible changes and deprecations.

I want to give a shoutout to Jacob Walls, Greg Chapman, and new contributor in a big way Tim Felix Beyer for major contributions.  Also to Sara Mildenstein and Philippee Rigaux for their first contributions to the code.  And to long-time contributors Mark Gothan, Malcolm Sailor, and Louis Bigo, and to everyone who made the system better with discussions here, bug reports, and articles, presentations, and mentions (thanks Carol Willing at PyCon!) of music21.  And to the Seaver Institute, NEH, and MIT for making so much possible!

v9 is a major milestone which I hope everyone will enjoy!  

Upgrade with

    pip3 install --upgrade music21

Thursday, October 27, 2022

Music21 v8 Released

 (this message should have gone out last month...)

I'm proud to release v8 of music21, the toolkit for computer-aided music analysis, score manipulation, computational musicology, etc. This release (technically 8.1) builds on 12.5 months of work from v7, and like all new big number releases has a few backwards incompatible changes from before, in exchange for cool new features.

Version 8 supports Python 3.8+, if you need Python 3.7 (such as on Google Colab which is now 3+ Python versions behind) stick to music21 v7. V8 is the first to fully support Python 3.10 and will receive patches to support Python 3.11 in the future. There will be a change to music21's Python support policy in v9: music21 v9 will support Python 3.10 and above only.

Big Changes

  • The biggest new improvement in v8 is an all new Dublin-Core / MARC based metadata system that allows for encoding a huge amount of information about a score. Look at the new docs for music21.metadata for more information. Thanks to Greg Chapman for the big amount of work on this.
  • Modern installation system, based on Hatch. If you have problems, please let me know -- I expect some growing pains on this.
  • ArpeggioMark and ArpeggioMarkSpanner classes.
  • Adding DCML v2 parsing to
  • Explicit Keywords on all music21 objects
  • Continued Major improvements in Typing across music21. If you are using a modern IDE, you will find the number of music21-related bugs you create will go down hugely.
  • Ever more docs and more relevant (and diverse examples)

Other changes/fixes since v7.3

  • opFrac speedup
  • Fix MIDI in Google Colab Notebooks (backported to 7.3.3)
  • Use more classes in getElementsByClass
  • Improve graphing docs and options
  • Accidentals never and if-absolutely-necessary
  • Add typing to
  • makeRests(inPlace=True) returns None for scores
  • StreamCore is now a Music21Object; Iterator improvements
  • Avoid <forward> tags from expressions out of measure bounds
  • Avoid writing empty <movement-title /> and <creator /> tags when title and author have no defaults
  • harmonicFunction. maps between RN figures and function labels
  • Make cautionaryPitchClass=True work with chords
  • Export Unpitched to MIDI
  • Fix getPitches(direction=DESCENDING) returning ascending scales
  • Make Key instances compare equal regardless of tonic octave
  • Fix midmeasure clef export regression involving voices
  • Fix a bug in musicxml/ where a clef-octave-change
  • Musicxml export: Preserve whitespace in TextBox
  • Fix bug in Capella parsing
  • Patch duration linked bugs
  • deprecate gcd in favor of C math
  • makeTies within makeNotation; getTimeSignatures recurse
  • First docs and improvements to trees
  • Fix shiftElements docs
  • SixthMinor carries to secondary dominants
  • Add makeNotation routines for completing or consolidating tuplets
  • Demonstrate ties in splitElementsToCompleteTuplets doctest
  • MusicXML export: Make rests before making notation
  • Validate figures provided to RomanNumeral()
  • Clear cache when adding notes w/o sort
  • match d43, d65, etc.
  • Use requests lib. for URL getting
  • Allow iterables of qualified class names in Stream.__getitem__ searches
  • Fix problem with add#7
  • Add makeNotation argument to test utility
  • Prevent too large <backup> values in PartStaffExporter
  • Prevent zero-duration ChordSymbols from matching stripTies algorithm
  • fixed up romanText repeats
  • Remove *arguments where not used
  • Standardize DatePrimitive -> Date interaction
  • Emphasize Pitches in Interval classes
  • Voice numbers written in MusicXML must be unique
  • Parse double flats in RomanText
  • Fix (and test) writing of multi-measure RepeatBrackets to MusicXML
  • romanText write to file-like objects
  • Closing too many TinyNotation states is now a TNException
  • Fix loss of forward repeat marks when exporting PartStaffs
  • Add typing for contextSites, yieldSites
  • Get rid of imp / load_source()
  • Remove tons of unnecessary imports in doctests
  • Clarify copyright entities
  • Use hatch for building

Sunday, March 27, 2022

Music21 v7.3 released

Music21 version 7.3 is released.  This is the second and probably final release on the v7 line.  I begin work on version 8 today.

Version 7.3 is a bug-fix, improvement, and maintenance release of music21.  Aside from a few obscure corners of the code, it is designed to be fully backwards compatible with the previous v7 releases (7.1).  It represents half a year's work since the original v7.1 release.

Thanks go especially to Jacob Tyler Walls who really steered the contributions to this release.

Among the major improvements in this branch are:

  • Full support for Python 3.10.
    • I've been doing all my recent dev on 3.10 taking advantage of new features, and it's great, and plays well with numpy, tensorflow, and so many other cutting edge analysis tools.
    • In keeping with music21's policy of supporting the last three versions of Python, music21 v7.3 will be the last version of music21 to support Python 3.7.  A decision on whether 3.8 or 3.9 will be the minimum version for music21 v8 will come later, depending on its release date; we may also update policy somewhat and raise the minimum version to 3.9 during the v8 cycle.
  • MIDI and MusicXML import/export will create and use Unpitched and PercussionChord objects. (slight incompatibility but worth it).
  • The stripTies method's "matchByPitch" setting is improved.
  • Slight incompatibility:  3/8 is default configured to one beat with two sub beats (like 6/8)
  • Lots more typing improvements.  mypy is now being run on a subset of the music21 code to ensure that our docs match our work.
  • Individual notes in Chords can be styled more easily and robustly.
  • The tree module is slightly better documented, for anyone who wants to work with insane speed (and complexity)
  • Some superfluous natural signs no longer appear after running makeNotation; makeAccidentals improvements throughout.  displayType="never" is now respected.
  • Improvements in instrument names and lookup (Thanks Mark Gotham)
  • Music21 gives better introspection in more developer environments. Music21 now imports its own modules individually.  The former way of doing its own imports while "legal" was preventing code analysis on some IDEs.
  • Dissonance score on certain compound intervals has been improved.
  • ChordSymbol constructor has been improved
  • Metronome marks only appear on the top staff of piano and other PartStaff scores.  Other superfluous meters and key signatures on various outputs (especially MIDI) have been fixed.
  • Braille exports voices properly; full scores including piano (PartStaff) export to Braille.
  • Ottava objects import better from musicxml
  • Bug fixes on changing RomanNumeral objects, or round-tripping chordFromFigure(romanNumeralFromChord(ch).figure), especially with bracketed alterations and on minor vi/VI/vio and vii/VII/viio
  • GarageBand is now set as the default MIDI player on MacOS.  It's a bit of overkill to be sure, but it's the only MIDI player that comes with the system, and to be honest, it sounds really good.
  • More .commonName improvements for enharmonic respellings of common chords.
  • TempoText preserves styles even if the text changes (thanks Greg Chapman)
  • RomanNumerals now treat common ways of inputting suspensions (V54, etc.) as suspensions rather than obscure 11th chords, etc.  Note, however, that RomanNumerals are not a fully consistent/comprehensive chord description format, so there will always be some gaps in coverage.
Smaller improvements and features include:

  • Root position Neapolitan chords can be written as "N53"
  • Better support for output on systems where UTF-8 is not the default.
  • Time Signatures export to MIDI
  • Instruments that normally have a certain transposition (Trumpet = Bb, etc.) now respect part parsing of "Trumpet in C"
  • More gaps in streams export to MusicXML as "forward" tags.
  • Braille output supports more technical indications beyond fingerings, such as bowings.
  • Hidden features in chord.tables are now exposed and documented.
  • chordReduction (beta) crashes less often. 
  • Figured bass input supports notation like "64" (same as RomanNumeral) in addition to the older "6, 4" syntax.
  • Date metadata supports error ranges better.
  • attachIntervalsBetweenStreams is now more robust on subsequent runs if the streams are being edited.
  • Some edge cases of ChordSymbol's with add/subtract/alter/omit have been fixed.
  • A corpus file with an offensive name has been renamed and edited.  It came from a bulk import of an existing collection that was never closely scrutinized.  There are files in the corpus from minstrel show traditions that would never been added today; however, because so many existing tutorials etc. rely on these files being in the corpus, they have not been removed now.  They may be in the future.
  • ChordSymbols with realized durations are exported properly.
  • Up to 2048th notes can now be beamed.
  • getSpannerSites can now take classes.
  • Correct spelling of "bemol" in Spanish.
  • localCorpus.removePath fixed.
  • harmony.NoChord improvements.
  • Faster MIDI import/export
  • Crescendo and Decrescendo wedges have correct and sane id numbers in musicxml output.
  • no longer occasionally finds things in other streams.
  • .show('musicxml') on a single measure is improved (and works well in Finale 27).
  • Users who choose to skip makeNotation on musicxml writing (in general don't!) will have exceptions thrown if notation that cannot appear in musicxml gets through, rather than just corrupt musicxml.  This does not affect the 99.9% of us who let music21 change notation to reflect what can be written in a score. 
  • TimeSignature.loadRatio() deprecated.  Use TimeSignature.load() [same] or TimeSignature.ratioString = '4/4'
  • Score.flattenParts() -- just iterate over .parts and call flatten() on that.
  • Duration.fill() -- this was a testing routine that got exposed.
Goals for the upcoming v.8 include support for MusicXML 4.0 and SMuFL and better round-tripping between various formats, cleaner typing, improved docs and faster operations.  Improved support for IDEs including Jupyter notebook and Colab will also be prioritized.

There are other new features, such as improving OMR post-processing, restoring the web/VexFlow 4.0 connection, etc., but (as people who have proposed major new features on GitHub will be aware), I'm planning on considering the core music21 largely "feature complete" and encouraging people to make external libraries (now that pip + GitHub makes this so much easier) rather than stuffing more into music21.  I'd rather focus music21 on being the core system for so much else than putting more into it.  I don't plan on removing anything currently in music21 in the next version, but you may find that they're being imported from other libraries instead.  This will let the community move at the pace some people there want while letting me guide the core project as 15 years of development on it has taught me.

As ever, music21 would not have been possible without support from the Seaver Institute, the National Endowment for the Humanities and the multinational Digging into Data challenge, and the support of MIT/SHASS/Music & Theater Arts.

Wednesday, September 8, 2021

Music21 v7 is released!

Version 7 (technically 7.1.0) of music21, a toolkit for computational musicology, music theory, composition, etc. is released!  A substantial revision and set of improvements for music21 that will make it easier to analyze, explore, and compose music.  As with all new major version releases, there are some incompatibilities with earlier versions that should make developers test their own software before upgrading.

Big improvements:

Why type:


When you can now type:


Or if you want to find the first Key object in the piece, don't type:


...which will walk through the entire score, even though you just want something at the beginning.  You can instead do:


in a millionth of the time.  Streams and StreamIterators get the .first() and .last() methods, though only .first() is currently a major speedup.  When we figure out how to walk an iterator quickly backwards, though, one day, .last() will also magically become faster.

Making a stream from notes could take a lot of space:

c = note.Note('C')
d = note.Note('D')
m = stream.Measure()
p = stream.Part()

So why not:

c = note.Note('C')
d = note.Note('D')
p = stream.Part(stream.Measure([c, d]))

now if a list of elements are passed into the stream constructor, they are appended one after another, not all inserted at position 0.  

If a stream is passed to another Stream's constructor it is put into the Stream itself, not its elements.  This was a common mistake in v6 and earlier:

c = note.Note('C')
m = stream.Measure(c)
p = stream.Part(m)
sc = stream.Score(p)

Before, since Streams are list-like, the only thing in the Score would have been the single note C with no parts or measures at all!

In v7, the code above will create a perfectly well-formed score (well, except the lack of TimeSignature, etc., but music21 can figure that out for you.

Oh, and if you put multiple Measures into a Part constructor, they're all appended as they should be.  Put put multiple Parts into a Score constructor or multiple Voices into a Measure constructor and they're all at offset 0, like they should be.  Smart is better than inflexible.  

Because of this change, there's now much more incentive to create proper Part, Measure, etc. objects than just making everything a general Stream.

Streams can now retrieve a single element with recursive search by id:


or easily iterate over all elements recursively by group:

for n in sc['.myGroup']: ...

If it looks like CSS querySelectors, it's for a reason.  And we're just getting started with showing the power of these elements.

Stream.flat has become Stream.flatten() -- why?  (a) it's a verb, and should be a verb.  (b) it takes a long time to generate and alters the .sites on the contained notes, so it shouldn't be a property, which implies that it's fast and has no side-effects.  (c) it is now no longer shorter and faster to type than Stream.recurse() which is what you want to do 90% of the time anyhow.  Stream.flat will stick around for at least 2 more versions, becoming deprecated in v8 or 9 and removed in v9 or 10.  I know it's our version of "print(a)" replacing "print a" and it'll take some time to get used to.  But it was a mistaken choice in 2008 and it's just as much of a mistake in 2021.

(For .semiFlat, just use Stream.flatten(retainContainers=True) which is much clearer)

New Core Developer: Jacob!

Jacob Tyler Walls has joined the commit/core development group of music21 and can now review your pull requests etc.  He has made MAJOR contributions to v7 and it would not be out without him!  Please send him your thanks when you use music21.  Because he's on the core team now, I won't single out his contributions separately from my own (for the most part.  When it's big, I'll say so).

Other substantial improvements

  • I hope you're editing your own files in a modern IDE like PyCharm or VSCode.  We've added tons of typing information to help you find bugs before you run.
  • Significant improvement in MIDI Quantization.  We still recommend converting MIDI to MusicXML (or Humdrum/MEI/etc.) in a dedicated MIDI processor, but many more MIDI files will work "out of the box" in music21 v7.
  • Go ahead and parse a large piano score from musicxml.  But don't go get your customary cup of coffee.  Jacob made it very fast now!  Lots of speedups!
  • PercussionChords or chords containing a mixture of Note and Unpitched objects are now supported!  We're getting much closer to equal support for percussion as for pitched music!
  • Multiple instruments can be in a part now and manipulated and exported to musicxml.  This works simultaneously in voices, successively (broken before in musicxml), or overridden on a single note basis with n.storedInstrument.
  • Full support for Python 3.9.  Python 3.10 also seems to work with m21v7, but is not officially supported.  Official support will come during the v.7 lifecycle unless it requires backward incompatible changes (unlikely).  In keeping with music21 policy to support the last three versions of Python, version 7 will be the last version of music21 to support Python 3.7. 
  • The representation of many music21 objects has changed and become standardized to give a lot more information (what type of rest is it?  What octave is the note in?)  This should help with debugging and shouldn't affect anyone unless you are parsing repr() for information.  (Don't do that).  If you are creating your own Music21Object subclasses define _reprInternal() to return just internal information beyond the class name to get it right.
  • Braille output respects lineLength configurations. Slurs work better too in braille.
  • MIDI import comes with measures already made for you!
  • roman.romanNumeralFromChord() recognizes a bunch more chords including all augmented sixth chords in all inversions (except German7 which I can't figure out).  And RomanNumeral now takes "It" alone to mean It+6, and same for the others -- it puts them in their most common inversions.  To get root-position Aug6 chords, spell out their figures explicitly:  It53, Ger7, Fr7, etc.
  • Ornaments now realize with their key contexts.  Trills are great.
  • MIDI input now preserves channel and program numbers for MIDI output.
  • Chris Reyes has contributed a formal grammar for TinyNotation which helped us find lots of bugs.  Thanks!
  • Write compressed musicxml directly by passing in a filename ending in .mxl.
  • getContextByClass has configuration options that when called on a Stream let them look inside themselves for their own context.
  • Beaming improvements in pickups and incomplete final measures.
  • MusicXML and MIDI files that give a part name like "flute" but no instrument or program code will get a Flute object in music21.  It's the least we can do.  And if a score sets a MIDI-0 instrument but no part name and only a single staff, it's probably a default value and not a piano, so we just give a generic Instrument object.

Incompatible Changes that might affect casual users:

  • Python 3.6 is no longer supported.  Stay with 6.7.1 if you need that.
  • The default extension for musicxml is now .musicxml and not .xml
  • MIDI import comes with measures already made
  • Stream.iter is now Stream.iter() -- the old format will work for one more version.  (Most people just do "for el in s" anyhow, so not a big deal.
  • findGaps() now returns Rest objects at the same place as the old Music21Objects.  Makes it easier to add them back to the Stream to fill gaps.
  • See above about if you're parsing repr() that representations have changed.
  • n.pitch.accidental = 'sharp' is no longer allowed.  Do n.pitch.accidental = pitch.Accidental('sharp') -- this is so that querying n.pitch.accidental afterwards returns the same object.
  • Stream.sorted has become Stream.sorted(), but you probably should never call this anyhow, since all streams are always sorted unless you set .autoSort to False.
  • stripTies() removes retainContainers parameter.  They're always retained.  Just call .flatten() after stripTies to remove them.  MatchByPitch is also True by default now.
  • Before running WindowedAnalysis on a Score, flatten it.  (This came from the makeMeasures change)
  • See the changes to instantiating a Stream with a list of elements above.
  • note.SpacerRest() is gone.  Use a normalRest with .style.hideObjectOnPrint set to True.
  • ComposerPopularityFeature is gone.  It was a fun routine that added the popularity of the composer by googling her or him and returning the log10 of the number of search results.  But Google changed their API so it was no longer working.  Too bad.   (It's not working in v6 either)
  • Dynamics, etc. now use "placement" instead of "positionPlacement"
  • Now that Percussion chords are being used and unpitched objects will appear more often, do not assume that the only things in ".notes" are Notes and Chords.  So if you want to call ".pitch" on the object, check that it is a Note, instead of checking that it is not a Chord.

Other improvements and fixes

  • Add TempoChangeSpanner with subclasses RitardandoSpanner and AccelerandoSpanner.  How these were missed is beyond me!
  • ABC supports more chord formats including better durations (thanks Marian Schultz)
  • Stream.splitAtDurations() now works and can efficiently remove all "complex" durations.
  • A number of places where "coreElementsChanged()" weren't being called now are.
  • NotRest objects all get .pitches attribute, which might be empty.  Version 8 will add this to Rest objects as well, which will of course always be empty.
  • Lots of docs typos fixed (thanks Meekohi)
  • Plaintext (non-Regexp) lyric searching had bugs that are fixed
  • Piano Scores can now have independent key signatures in each hand imported and exported to musicxml properly.  Go play "The Alcotts" now.  :-)
  • Cross-staff spanners in piano scores import much better.
  • Lots of special strings and ints have become Enums.  Expect more in the future.
  • MakeMeasures can be run on a score without losing its part information.
  • Running Score.measures(24, 26) etc. will only get spanners relevant to that measure range, not every darn slur in the score!
  • Speedups now that the minimum Python version 3.7 has dictionaries that preserve insertion order.
  • Bold + Italic text exports to musicxml properly.
  • Added common.misc.unique which gets a unique list from an iterator while preserving order (unlike set)
  • Meter has been split into four modules to make it easier for someone to figure out how TimeSignatures work without needing to read about AccentSequences first.  TimeSignatures are much faster to generate.
  • Lots more docs in the duration module.
  • Decent beams in output of a score w/o explicit time signatures
  • When you mistype a path into converter, now you'll get a FileNotFoundError rather than music21 trying to parse the path name as a type of notation.
  • simplifyEnharmonics on a Chord can now be given a keyContext to figure out a better way of reducing accidentals (thanks gulnazaki!)
  • ChordSymbol objects transpose properly to a new ChordSymbol that reflects its current bass/root etc.
  • Chord.isTranspositionallySymmetrical -- can the chord be transposed up some number of semitones between 1 and 11 and get the same pitch classes?  Also has a requireIntervallicEvenness which checks if it is a tritone-dyad, augmented triad, diminished-seventh chord, wholetone scale, etc. for which inversion cannot be determined by ear.
  • hyphen-to-camelCase is now way faster, so is elementOffset() -- this would be a "so-what" except that together with an improvement to duration creation they speed up MusicXML parsing by almost 40%.
  • Spanner.getSpannedElementIds is sped up.  Again a so what?  Well, it's 75% faster MusicXML output for scores with spanners such as slurs, etc.
  • Duration.expressionIsInferred attribute.  Think that a QL of 0.5 is always an eighth note?  Well, if it's between 0.333 and 0.16666 it might be a dotted-eighth triplet.  When a note is set with a quarter length, expressionIsInferred is True, and music21 is allowed to renotate it to fit the context.  A note with duration 2.5 might be quarter + dotted quarter in 5/8 as 2+3 but might be the opposite in 3+2 5/8.  Not fully implemented, but something for the future.
  • Lots of little speedups all around.
  • Full measure rests now work in 9/8 and some other meters where there is no way of expressing a note of that length, but we can for rests with a Whole Note.
  • Improvements to NeoRiemannian operations on MIDI-generated notes.  Thanks ax-le.
  • Dynamics, wedges, coda, segno, and tempo markings retain their positions on musicxml import/export.  And thanks to Gesellkammer metronome marks also know if they're above or below the staff.
  • makeTies() works better when a note inside a voice is tied to a note outside of a voice.  No unnecessary voices made.
  • TAB staves always have notes that are stem down.  (Thanks Louis Bigo)
  • DataSet.write() now tells you the filepath that was written.  (Duh!)
  • Add Chord.hasAnyEnharmonicSpelledPitches()  -- C4 E4 G4 B#4 returns True
  • isItalianAugmentedSixth etc. gains a permitAnyInversion=False keyword which can be set to True to find unusual inversions of augmented 6th chords.  Oh, and they're much simpler and faster (if it matters)
  • Mordents etc. return GenericIntervals when realized so that they can take into account key signatures.
  • Finding the root of a chord is much, much faster.  That's something that's needed for lots of analytical methods.
  • i7 and iv7 are now minor seventh chords when in a Major key.  So C-Eb-G-Bb.  To get a minor-major chord, spell it as i[add7].  Tonic minor-major chords in third inversion in major currently have no representation.  I think that that's a very rare case that this is an improvement for everyone.
  • FrontAlteration symbols are fixed for Neapolitan and AugmentedSixth roman numerals.
  • Add common.classTools.tempAttribute and saveAttributes context-managers for temporarily setting an attribute to something else and restoring it afterwards.  (just a helper)
  • Stream.duration is much better about detecting non-standard ways of altering containing note durations.  Thanks Greg Chapman for finding the bug.
  • MusicXML can import measures containing only ChordSymbols (empty leadsheets)
  • converter.parse() with a URL can now also take forceSource=True to redownload a file from the net.
  • Scores generated by .template() now export repeats properly.
  • makeTies() takes a classFilterList now.
  • makeRests puts rests properly in measures.  So you can do.  s = stream.Stream(); s.append(meter.TimeSignature('4/4')); s.insert(9, note.Note()); call makeRests() and get two full bars of rests, a quarter rest, and then your note and rests afterwards!
  • MusicXML input now handles notes that have different durations than the typical modern length implied by their shape (handy for contemporary music and the baroque).
  • TimeSignatures of 3.0/4.0 are now identified as an error before they're parsed into something weird. (Thanks Luke Poeppel)
  • Gracenote and appogiature display improvements.
  • Crashes in feature extraction should be less rare as more common edge cases are handled.
  • GraceNotes no longer interfere with beaming.
  • .melodicIntervals() works with Chords now too.
  • Lilypond output fixes and improvements.  With Lilypond now having a native Mac-64bit app, it is no longer under threat of being removed from music21.
  • Various write/show routines now work in multi-user Unix environments where users do not have write access to the normal temp folder.  (Thanks tanchihpin0517)
  • Improvements to TwelveToneRow.areCombinatorial()  (Thanks Mark Gotham)
  • KeySignature objects can now run asKey(tonic='A') and will try to find what mode has this key signature with that tonic.
  • Substantial improvements in Stream.findConsecutiveNotes() including with and without voices.
  • advanced users who need a very fast output of a Score which has already been asserted to be well-formed can call .write(makeNotation=False), which will not create any beams, tuplets, etc.  Unless you are a power user who needs the extra speed for processing thousands of files, and who can run a debugger to see what is wrong, don't use this.  It's going to crash on you.  But for those who do need it, the speedup is tremendous.
  • Transposing instruments set to .atWrittenPitch now display at written not sounding pitch in musicxml output.
  • Add Electric Piano and Choir instruments.
  • Music21 via pip will always be installed with the correct requirements (thanks James Owers)
  • Very long notes can now be shown via .show() and will be broken up into multiple measures.
  • Add Chord.inversionText to easily get "First inversion" "Root position" etc.  For unusual augmented sixth chord inversions, we add this text to the common name.
  • Smarter decisions on when to rearticulate an accidental after a key change.
  • Successful writing to MuseScore PNG/PDF will not fill your console with junk.

Deprecated methods/etc. that you were warned about that have been removed: 

  • Chord.findRoot() [dep. since 2018] is gone. Just use Chord.root()
  • Editorial.misc['anyKey'] is gone.  Just use Editorial.anyKey instead.
  • humdrum.parseFile() and humdrum.parseData() are gone. [Dep. since v6] Just call converter.parse('myFile.krn') instead.  These functions stuck around for way too long since they appear in the original music21 publications, but time changes.
  • interval.convertSpecifier() is gone. [dep v6]  use interval.parseSpecifier() instead, which returns a interval.Specifier enum instead. 
  • Roman.scaleOffset is removed.  Use the identical .frontAlterationTransposeInterval instead.

Incompatible changes that will only bite real music21 fanatics:

  • setElementOffset has addElement and setActiveSite removed as options
  • Environment.launch() no longer raises CalledProcessError
  • Duration.updateQuarterLength() is gone/private.  QuarterLengths should always automatically match the type/dots/tuplet, etc. unless "unlinked".
  • Harmony.addChordStepModification() sets default for updatePitches to True. 
  • Roman.followsKeyChange is now Roman.editorial.followsKeyChange
  • makeAccidentals inPlace defaults to False.
  • Stream.__init__ is mostly in Stream.base now.
  • We've taken advantage of Python 3.7's module level __dir__ to remove things you don't want to see from dir(module)
  • A number of string/int returns have become StrEnums or IntEnums which can compare to their old values (i.e., OffsetSpecial.AT_END == 'highestTime'), but if you're doing isinstance checking then it's not going to work.  Relatedly getOffsetBySite(returnString=True) becomes getOffsetBySite(returnSpecial=True)
  • Stream.quantize() has recurse=False by default, matching other music21 methods.
  • StripTies() inPlace=True now returns None like other inPlace=True methods.
  • Meter split into 4 modules.
  • test/ is now stream/
  • duration.durationTupleFromQuarterLength and durationTupleFromTypeDots are gone -- just create a Duration object with a given quarterLength or type and dots instead.  (made private on Duration)
  • setDefaultBeatPartitions moves forceCompound to a keyword only attribute.
  • default for key.KeySignature() is now no-sharps or flats rather than None (non-standard key signature).
  • Style objects are ProtoM21Objects.
  • Spanner.replaceSpannedElement() only takes Elements not memory locations.
  • hasAnyRepeatedDiatonicNote removes the useless testRoot keyword.
  • Realizing a mordent or trill or turn will give a different (now correct) result in a key context.  
  • See the change to "It" to mean "It6" etc.
  • See changes to i7 and iv7 in Major.
  • makeRests puts rests properly in measures.
  • Many music21 specific exceptions have been replaced by very similar general Python exceptions.  Grabbing an element that doesn't exist from a stream, like s[123999] raises an IndexError not a StreamException, for instance.
  • Ambitus.getPitchRanges() is removed.  Just do stream.analyze('ambitus')
  • .mx is no longer an abbreviation for musicxml.
  • Now that isinstance() is very fast on Python, we use that a lot internally.  This will only bite people who are loading modules from two different installations of music21 somehow (like using a package that includes its own version of music21).  Otherwise just enjoy the speed.
  • Chord now inherits from ChordBase to support having the same features on PercussionChord
  • Stream.extendDurationsAndGetBoundaries is gone -- did too many things at once.

New Deprecations

  • Stream.variants.  Call Stream[variant.Variant] or Stream.getElementsByClass(variant.Variant) instead.
  • Score.flattenParts().  Basically unused.  Iterate over and call .flatten() on each of them.
  • common.Iterator. You haven't been using Python 2.6 for years, so you don't need it.
  • Duration.fill().  Was just a test function and we don't put them on objects any more.
  • TimeSignature.loadRatio().  Create a new TimeSignature or set .ratioString = '4/4' or .load()
  • TimeSignature.beatDuration returns NaN rather than raising an exception if beats are unequal.
  • common.almostEquals.  Since Python 3.4, Math.isclose() is better.
  • Spanner.getSpannedElementById().  Of course you never used this.
  • Stream.makeChords().  Use chordify() instead.
  • Stream.getKeySignatures().  Use getElementsByClass(key.KeySignature)
  • Stream.getClefs().  use getElementsByClass(clef.Clef) or getContextByClass(clef.Clef) or bestClef() depending on what you want.
  • VoiceleadingQuartet.color.  Use .style.color instead.
  • Note that isClassOrSubclass was slated to be deprecated in v7, but it was found to be too useful to remove completely.  Nonetheless, we prefer isinstance(n, note.Note) instead.

This was a HUGE amount of work since v6.7 released in February.  Super proud of the community for making it possible.  If you're on a version older than 6.7, here are the biggest things you're missing:

6.7 -- Composite lyrics: multiple syllables on one note
6.5 -- PartStaff round-tripping to musicxml, RomanText output, better lyric searching
6.3 -- Compatibility with macOS Big Sur and Python 3.8
6 -- Type-hinting, no external modules bundled, interval fixes
5.7 -- big bug squashing.  Chorale metadata.  Chord.notes tools
5.5 -- Chord.commonName improvements. Volpiano.  Cad64
5.3 -- ABC parsing improvements. containerInHierarchy. Py 3.7 support
5 -- Chordify massive speedups. MusicXML style preservation.  Multiprocessing AI/ML
4 -- Graphing rewrite.  Local Corpora.  Style objects.  TinyNotation subclassing. Direct PDF generation
...and the list goes on.

Thanks always to the Seaver Institute, MIT, and the National Endowment for the Humanities for supporting music21.

Wednesday, February 3, 2021

Music21 v6.7 released

music21 v6.7 is released. This will likely be the last release on the v6 line (more later), which has seen remarkable speed and stability improvements. Here’s what’s new in the past month since 6.5 came out:

  • Important bug fix: if you’ve had trouble loading music21 with an “importlib” error, this is fixed.
  • Composite lyrics changes to the implementation in 6.5: multiple syllables on one note in a single verse (like in Italian, “Il bianco edolce cigno”) now are imported to MusicXML property, stored in a Lyric.components object, and export to MusicXML properly.
  • Lyrics searching finds all lyrics in all verses (and composite lyrics too)
  • More major improvements to piano staff imports (thanks to Jacob Tyler Walls = JTW)
  • RomanNumeral.isMixture() shows whether a chord is borrowed from the other mode (Mark Gotham)
  • Several improvements in chord symbols (JTW + Alexandre Papadopoulos)
  • More improvements to finding instrument names from MIDI (JTW)
  • Duration marks in chords in ABC import properly (Marian Schultz)
  • Documentation improvements.
  • MusicXML parse failures now more often give the part and measure context (JTW)
  • Substantial bug fixes in Stream.setElementOffset. Adds a new Stream.coreSetElementOffset for the dangerous but super fast version, and makes the original version safer. (JTW)
  • Bug fixes in MEI articulations (heinzer) and accidentals (JTW)
  • Bug fixes in external tools in windows including spaces (JTW)
  • Channels handle better in MIDI (bearpelican)
  • Humdrum files with positioned rests no longer crash (Phil Kirlin)
  • OctaveRepeatingScale and CyclicalScale now usable as abstract classes (JTW)
  • Articulations and expressions musicxml does not support are exported as (JTW)
  • Better support for .musicxml as a file name within compressed .mxl files.
  • Beaming in pickup measures is fixed.
  • Stem directions can now be set automatically to coincide with beam groups. This is very useful if you are creating your own notation from scratch (as in VexFlow output; m21j gets the same routines)
  • Spanner endHeight and startHeight are processed correctly (JTW)
  • NoChord objects (in Chord Symbols) now retain their text (like “N.C.”) in more situations (JTW)
  • All NotRest objects get a .pitches function – a small thing, but will be helpful in the future.

6.7 is likely the last release in version 6. We begin work on version 7 today! This means that most deprecated functions will be removed, to speed up the system and help build new things.

  • Version 7 will require Python 3.7 as a minimum version. Python 3.6 will be end-of-life by November, and v.7 will last for at least into 2022. music21 will continue to support all Python versions that are actively maintained during the expected life of the version. v3.7-3.9 will be supported, and when 3.10 comes out, the next minor version of music21 will support it.

But dropping Py3.6 means some great changes:

  • Many things that are NamedTuples will become dataclasses. (all but sortTuple). This will make working with a lot of data much better.
  • Many many string options (such as notehead and beam types) will become Enums. This will help with avoiding making coding mistakes that are hard to detect. Where this has already happened (like in VoiceLeadingQuartet.MotionType) life has already become better. They will be StringEnums, and have a transition period, so code that checks for Beam.type == “start” or Lyric.syllabic == “begin” will still work (but I can never remember which is start and which is begin. Hence the point!)
  • Substantial changes to Unpitched to make percussion support work.
  • Some OrderedDicts (yuk!) will become normal dictionaries, now that insertion order is guaranteed to be preserved.
  • Whatever else has been annoying me but I haven't been able to fix by committing to keep major versions backwards compatible.
  • For simplifying the life of beginner users, __getattr__ and __dir__ will be defined for certain key modules (like Note) so that all the typing and internal information isn't exposed.
  • I'm hoping that getElementsByClass will be able to specify its return type, at least when called with a class. For people using Typing in Python, this will be a major improvement.

Deprecated functions gone ASAP:

  • Chord.findRoot() -- just use chord.root() instead
  • interval.convertSpecifier – use parseSpecifier instead
  • formats.findFormat (and many others in the formats module etc.)
  • humdrum.parseData, humdrum.parseFile (just use converter.parse)
  • Editorial.misc (just stick it on editorial)
  • Duration.updateQuarterLength (not needed)

New deprecations

  • SpacerRest will become deprecated – just use a normal Rest with hideObjectOnPrint = True
  • Setting a pitch.accidental to a number or string will be deprecated – create an Accidental object first
  • setElementOffset deprecates two keywords: addElement and setActiveSite
  • isClassOrSubclass to be deprecated, use Class in .classSet – WAY faster
  • getClefs to be deprecated – use recurse().getElementsByClass(‘Clef’)
  • getKeySignatures to be deprecated -- use recurse().getElementsByClass(‘KeySignature’)
  • Stream.makeChords() to be deprecated – Chordify is the way to go.
  • Stream.extendDurationsAndGetBoundaries – was meant to be deprecated in 6 and gone in 7. It gets a one version reprieve.
  • stripTies.retainContainers to be deprecated – will always be True. Just call .flat afterwards to not get this.
  • Stream.iter.variants to be deprecated. Just use .getElementsByClass(‘Variant’)
  • tree.toStream.chordified() to be deprecated. It’s the internal guts of Chordify now
  • VoiceLeading.color to be deprecated – set .style.color on notes like any other object

Weird changes of properties to methods:

  • Stream.iter() will be the encouraged new form instead of Stream.iter
  • Stream.sorted() will be encouraged new form instead of Stream.sorted
  • (This might not happen, but...) Stream.flat() encouraged for Stream.flat -- similarly for .semiFlat
  • Other properties where it is possible to encourage method calling will also get this change.

These methods were disguised as properties early on in music21 and it was a bad mistake, leading to lots of problems with introspection. Migration will go like this: v7 -- new forms are allowed and documentation is updated to encourage it. v8 -- all mention of old forms will be removed from the system and where possible using the old form will send a DeprecationWarning. v9 -- old forms are removed.

Version 7 might take until the summer or beyond. (Hence there may be bug-fix versions of v6.7 along the way). So for now, enjoy what’s out there and look forward to the future. The main branch will move to v7 but will remain as stable as possible.

Thanks to the community for great support and as always to the Seaver Institute, National Endowment for the Humanities, and MIT for support of music21.