User’s Guide, Chapter 10: File Formats (1)¶
Music21 can import and export a variety of musical data formats. Many examples of these formats are distributed with music21 as part of the corpus module (see music21.corpus).
The converter module, as well as the module function
music21.converter.parse()
handle importing all supported
formats. For complete documentation on file and data formats, see
music21.converter.
Parsing MusicXML Files¶
We can parse a MusicXML file by providing the
music21.converter.parse()
function with a local file path or an
URL to a file path. The function will determine the file format. An
appropriate Stream
or Stream subclass will be
returned. For example, given a MusicXML file stored at the file path
“/Users/cuthbert/_scratch/bwv1007-01.xml”, a Stream can be created from
the file with the following.
from music21 import *
c = converter.parse('/Users/cuthbert/Desktop/myXML.xml')
Alternative, we can provide a URL to the
music21.converter.parse()
function that points to the desired
file. Assuming proper system configuration (see Configuring Environment Settings),
the file will be downloaded and parsed.
url = 'http://kern.ccarh.org/cgi-bin/ksdata?l=cc/bach/cello&file=bwv1007-01.krn&f=xml'
sAlt = converter.parse(url)
sAlt[1][:6].show() # show first 5 measures

Note that presently music21 offers limited support for compressed .mxl MusicXML files; this feature will be expanded in the future.
Getting MusicXML Files¶
Numerous MusicXML files can be found at the following URLs.
Parsing Humdrum Files¶
Parsing Humdrum files is exactly as parsing other data formats. Simply call the music21.converter.parse() function on the desired file path or URL.
sBach = converter.parse('http://kern.ccarh.org/cgi-bin/ksdata?l=users/craig/classical/bach/cello&file=bwv1007-01.krn&f=kern')
Getting Humdrum Files¶
Over one hundred thousand Kern files can be found at the following URL.
Parsing ABC Files¶
Parsing ABC files is exactly as parsing other data formats. Simply call
the music21.converter.parse()
function on the desired file path
or URL.
o = converter.parse('/Users/cuthbert/Documents/Music21/praludium.abc')
Note that many ABC files define more than one complete musical work. If
an ABC file defines more than one work, an
Opus
object is returned. Opus objects, a
Stream subclass, provide convenience methods for accessing multiple
Score objects.
Reference work numbers (e.g., the “X:” metadata tag in ABC) are stored
in Metadata
objects in each contained
Score. Access to these numbers from the Opus is available with the
music21.stream.Opus.getNumbers()
method. Additionally, the
Score
object can be directly obtained with
the getScoreByNumber()
method.
o = corpus.parse('josquin/ovenusbant')
o.getNumbers()
['1', '2', '3']
s = o.getScoreByNumber(2)
s.metadata.title
'O Venus bant'
Direct access to Score objects contained in an Opus by title is
available with the getScoreByTitle()
method.
o = corpus.parse('essenFolksong/erk5')
s = o.getScoreByTitle('Vrienden, kommt alle gaere')
In some cases an ABC file may define individual parts each as a separate
score. When parsed, these parts can be combined from the Opus into a
single Score with the music21.stream.Opus.mergeScores()
method.
o = corpus.parse('josquin/milleRegrets')
s = o.mergeScores()
s.metadata.title
'Mille regrets'
len(s.parts)
4
Getting ABC Files¶
Large collections of ABC are available from numerous on-line repositories. The following links are just a few of the many resources available.
Parsing Musedata Files¶
Both stage 1 and stage 2 Musedata file formats are supported by Music21.
Multi-part Musedata (stage 2) files, zipped archives, and directories
containing individual files for each part (stage 1 or stage 2) can be
imported with the music21.converter.parse()
function on the
desired file path or URL.
Note that access restrictions prevent demonstrating Musedata conversion.
Parsing MIDI Files¶
MIDI input and output is handled in the same was other formats. Simply
call the music21.converter.parse()
function on the desired file
path or URL.