music21.metadata

Classes and functions for creating and processing metadata associated with scores, works, and fragments, such as titles, movements, authors, publishers, and regions.

The Metadata object is the main public interface to metadata components. A Metadata object can be added to a Stream and used to set common score attributes, such as title and composer. A Metadata object found at offset zero can be accessed through a Stream’s metadata property.

The following example creates a Stream object, adds a Note object, and configures and adds the title and composer properties of a Metadata object.

>>> s = stream.Score()
>>> p = stream.Part()
>>> m = stream.Measure()
>>> m.append(note.Note())
>>> p.append(m)
>>> s.append(p)
>>> s.insert(0, metadata.Metadata())
>>> s.metadata.title = 'title'
>>> s.metadata.composer = 'composer'
>>> s.show()

A guide to the v8+ Dublin Core implementation:

The class Metadata has been completely rewritten in music21 v8 to support significant new functionality.

The previous Metadata implementation had a list of supported workIds, and also a list of standard contributor roles. More than one of each contributor role could exist, but only one of each workId. And while there was some support for custom contributor roles, there was no support for other custom metadata, only the specified list of workIds.

In the v8 implementation, contributor roles are treated the same as other non-contributor metadata. Music21 includes a list of supported property terms, which are pulled from Dublin Core (namespace = ‘dcterms’), MARC Relator codes (namespace = ‘marcrel’), and Humdrum (namespace = ‘humdrum’). Each property term is assigned a unique name (e.g. ‘composer’, ‘alternativeTitle’, etc).

Each metadata property can be specified by ‘uniqueName’ or by ‘namespace:name’. For example: md[‘composer’] and md[‘marcrel:CMP’] are equivalent, as are md[‘alternativeTitle’] and md[‘dcterms:alternative’]. There can be more than one of any such item (not just contributors). And you can also have metadata items with custom names.

For simple metadata items, like a single title, there is an easy way to get/set them: use an attribute-style get operation (e.g. t = md.title). This will always return a single string. If there is more than one item of that name, a summary string will be returned. To see the full list of metadata items in their native value type, use a dictionary-style get operation (e.g. titles = md[‘title’]). If an item or list of items is set (whether attribute-style or dictionary-style), any existing items of that name are deleted. To add an item or list of items without deleting existing items, use the md.add() API. See the examples below:

Set a title (overwrites any existing titles):

>>> md = metadata.Metadata()
>>> md.title = 'A Title'
>>> md.title
'A Title'
>>> md['title']
(<music21.metadata.primitives.Text A Title>,)

Set two titles (overwrites any existing titles):

>>> md['title'] = ['The Title', 'A Second Title']
>>> md['title']
(<music21.metadata.primitives.Text The Title>,
<music21.metadata.primitives.Text A Second Title>)
>>> md.title
'The Title, A Second Title'

Add a third title (leaves any existing titles in place):

>>> md.add('title', 'Third Title, A')
>>> md['title']
(<music21.metadata.primitives.Text The Title>,
<music21.metadata.primitives.Text A Second Title>,
<music21.metadata.primitives.Text Third Title, A>)
>>> md.title
'The Title, A Second Title, A Third Title'

You can also set/add/get free-form custom metadata items:

>>> md.setCustom('modification description', 'added missing sharp in measure 27')
>>> md.getCustom('modification description')
(<music21.metadata.primitives.Text added missing sharp in measure 27>,)

Adding another custom element for the same description creates a second entry.

>>> md.addCustom('modification description', 'deleted redundant natural in measure 28')
>>> md.getCustom('modification description')
(<music21.metadata.primitives.Text added missing sharp in measure 27>,
 <music21.metadata.primitives.Text deleted redundant natural in measure 28>)

Metadata does not explicitly support client-specified namespaces, but by using getCustom/addCustom/setCustom, clients can set anything they want. For instance, to embed the old SoundTracker .MOD format’s sample name, a .MOD file parser could use md.addCustom(‘soundtracker:SampleName’, ‘Bassoon’), and a .MOD file writer that understood ‘soundtracker:’ metadata could then write it back accurately to one of those files. Custom metadata (whether namespaced this way, or free form) can also be written to various other file formats without interpretation, as long as there is a place for it (e.g. in the ‘<miscellaneous>’ tag in MusicXML).

In music21 v8, primitives.Text has been updated to add isTranslated to keep track of whether the text has been translated, as well as an encoding scheme, that specifies which standard should be used to parse the string. See metadata/primitives.py for more information.

AmbitusShort

class music21.metadata.AmbitusShort(semitones, diatonic, pitchLowest, pitchHighest)

Metadata

class music21.metadata.Metadata(**keywords)

Metadata represent data for a work or fragment, including title, composer, dates, and other relevant information.

Metadata is a Music21Object subclass, meaning that it can be positioned on a Stream by offset and have a Duration.

In many cases, each Stream will have a single Metadata object at the zero offset position.

To get a simple string, use attribute-style access by unique name. Some workIds from music21 v7 have been renamed (e.g. ‘date’ has been renamed to ‘dateCreated’). The old music21 v7 name in these cases is still supported when you use attribute-style access.

>>> md = metadata.Metadata(title='Concerto in F')
>>> md.title
'Concerto in F'

Attribute access also works with three-letter workId abbreviations (these are grandfathered in from music21 v7; abbreviations have not been added for new-in-v8 metadata items):

>>> md = metadata.Metadata(otl='Concerto in F')
>>> md.otl
'Concerto in F'
>>> md.title
'Concerto in F'

It is also possible to set a list/tuple of values or get a tuple full of (richer-typed) values using dictionary-style access.

>>> md = metadata.Metadata()
>>> md['composer'] = ['Billy Strayhorn', 'Duke Ellington']
>>> md['composer']
(<music21.metadata.primitives.Contributor composer:Billy Strayhorn>,
 <music21.metadata.primitives.Contributor composer:Duke Ellington>)
>>> md.composer
'Billy Strayhorn and Duke Ellington'
>>> md.contributors
(<music21.metadata.primitives.Contributor composer:Billy Strayhorn>,
 <music21.metadata.primitives.Contributor composer:Duke Ellington>)

Here is the list of grandfathered v7 synonyms, which may disappear in a future version:

>>> sorted(metadata.properties.ALL_MUSIC21_WORK_IDS)
['commission', 'date', 'dedication', 'volume']

And here are their new v8 standard unique names:

>>> sorted(metadata.properties.MUSIC21_WORK_ID_TO_UNIQUE_NAME.values())
['commissionedBy', 'dateCreated', 'dedicatedTo', 'volumeNumber']

Metadata bases

• Music21Object

• ProtoM21Object

Metadata read-only properties

Metadata.bestTitle

Get the title of the work, or the next-matched title string available from a related parameter fields.

>>> md = metadata.Metadata(title='Third Symphony')
>>> md.bestTitle
'Third Symphony'

>>> md = metadata.Metadata(popularTitle='Eroica')
>>> md.bestTitle
'Eroica'

>>> md = metadata.Metadata(
...     title='Third Symphony',
...     popularTitle='Eroica',
...     )
>>> md.bestTitle
'Third Symphony'

>>> md.popularTitle
'Eroica'

>>> md.otp
'Eroica'

bestTitle cannot be set:

>>> md.bestTitle = 'Bonaparte'
Traceback (most recent call last):
AttributeError: can't set...

Metadata.contributors

Returns a tuple of all the Contributors found in the metadata. Returns an empty tuple if no Contributors exist.

>>> md = metadata.Metadata()
>>> md.composer = 'Richard Strauss'
>>> md.librettist = 'Oscar Wilde'

When we add something that is not a person, such as a title (whether through .attribute setting, [item] setting, or the add() method), it will not show up in the list of contributors.

>>> md.add('title', 'Salome')
>>> contribs = md.contributors
>>> contribs
(<music21.metadata.primitives.Contributor composer:Richard Strauss>,
 <music21.metadata.primitives.Contributor librettist:Oscar Wilde>)

Note that .contributors cannot be set. Add them separately via specific setters or the .addContributor() method.

Metadata.software

Returns a tuple of software names/versions.

Returns an empty tuple if no software names/versions exist, but this is rare, since music21 adds its own version when initializing a Metadata object.

>>> md = metadata.Metadata()
>>> md.software
('music21 v...',)
>>> md.add('software', 'Finale for Macintosh')
>>> md.software
('music21 v...',
 'Finale for Macintosh')
>>> md['software']
(<music21.metadata.primitives.Text music21 v...>,
 <music21.metadata.primitives.Text Finale for Macintosh>)

Note that .software is an exception to the general rule that singular looking properties return a string. In fact, it is always plural and returns a tuple of strings. There is no singular version

Read-only properties inherited from Music21Object:

beat beatDuration beatStr

beatStrength hasEditorialInformation

hasStyleInformation measureNumber

Read-only properties inherited from ProtoM21Object:

classSet

classes

Metadata read/write properties

Metadata.alternativeTitle

Get or set the alternative title.

>>> md = metadata.Metadata(popularTitle='Eroica')
>>> md.alternativeTitle = 'Heroic Symphony'
>>> md.alternativeTitle
'Heroic Symphony'

Metadata.composer

Get or set the composer of this work. Only the first composer can be got or set via properties.

The composer attribute does not live in Metadata, but creates a Contributor object in the .contributors object.

>>> md = metadata.Metadata(
...     title='...(Iphigenia)',
...     )
>>> md.composer = 'Shorter, Wayne'

You can set multiple composers by setting them dictionary-style or by using md.add. >>> md.add(‘composer’, ‘Spalding, Esperanza’)

The Metadata.composer attribute returns a summary string if there is more than one composer.

>>> md.composer
'Shorter, Wayne and Spalding, Esperanza'

Metadata.composers

Get a tuple or set an iterable of strings of all composer roles.

>>> md = metadata.Metadata(title='Yellow River Concerto')
>>> md.composers = ['Xian Xinghai', 'Yin Chengzong']

(Yin Chengzong might be better called “Arranger” but this is for illustrative purposes)

>>> md.composers
('Xian Xinghai', 'Yin Chengzong')

Might as well add a third composer to the concerto committee?

>>> contrib3 = metadata.Contributor(role='composer', name='Chu Wanghua')
>>> md.add('composer', contrib3)
>>> md.composers
('Xian Xinghai', 'Yin Chengzong', 'Chu Wanghua')

If there are no composers, returns an empty list:

>>> md = metadata.Metadata(title='Sentient Algorithmic Composition')
>>> md.composers
()

Metadata.copyright

Returns the copyright as a str. Returns None if no copyright exists in the metadata. Returns all the copyright values in one string (with ‘, ‘ between them) if multiple copyrights exist in the metadata. Use md[‘copyright’] to get all the copyrights as Copyright objects.

>>> md = metadata.Metadata()
>>> md.copyright is None
True
>>> md.copyright = 'Copyright © 1896, Éditions Durand (expired)'
>>> md.copyright
'Copyright © 1896, Éditions Durand (expired)'

Using dictionary-style access, you can use either the uniqueName (‘copyright’) or the namespaceName (‘dcterms:rights’). Here you can see how multiple copyrights are handled.

>>> md.copyright = 'Copyright © 1984 All Rights Reserved'
>>> md.copyright
'Copyright © 1984 All Rights Reserved'

To add another copyright to the list, call md.add().

>>> md.add('copyright', 'Lyrics copyright © 1987 All Rights Reserved')

md.copyright will now return both copyrights in one string

>>> md.copyright
'Copyright © 1984 All Rights Reserved, Lyrics copyright © 1987 All Rights Reserved'

md[‘copyright’] will return a tuple containing both Copyright objects.

>>> md['copyright']
(<music21.metadata.primitives.Copyright Copyright © 1984 All Rights Reserved>,
 <music21.metadata.primitives.Copyright Lyrics copyright © 1987 All Rights Reserved>)

You can set str, Text, or Copyright values, and they will be converted to Copyright automatically if necessary. Note that ‘dcterms:rights’ is Dublin Core terminology for ‘copyright’, and can be used interchangeably with ‘copyright’ as a metadata dictionary-style key.

>>> md.copyright = metadata.Text('Copyright © 1984')
>>> md['copyright']
(<music21.metadata.primitives.Copyright Copyright © 1984>,)
>>> md.copyright = metadata.Copyright('Copyright © 1985', role='something')
>>> md['dcterms:rights']
(<music21.metadata.primitives.Copyright Copyright © 1985>,)

Metadata.date

The .date property is deprecated in v8 and will be removed in v10. Use dateCreated instead.

Metadata.dateCreated

Get or set the creation date of this work as one of the following date objects:

DateSingle, DateRelative, DateBetween, DateSelection,

>>> md = metadata.Metadata(
...     title='Third Symphony',
...     popularTitle='Eroica',
...     composer='Beethoven, Ludwig van',
...     )
>>> md.dateCreated = '1805'
>>> md.dateCreated
'1805/--/--'

>>> md.dateCreated = metadata.DateBetween(['1803/01/01', '1805/04/07'])
>>> md.dateCreated
'1803/01/01 to 1805/04/07'

Metadata.fileFormat

Get or set the file format that was parsed.

Metadata.fileNumber

Get or set the file number that was parsed.

Metadata.filePath

Get or set the file path that was parsed.

Metadata.librettist

Gets or sets a single librettist for this work:

>>> md = metadata.Metadata(title='Death of Klinghoffer, The')
>>> md.librettist = 'Goodman, Alice'
>>> md.librettist
'Goodman, Alice'

To preserve continuity with Humdrum, library catalogues, etc., librettists should be distinguished from lyricists etc., but sometimes the line is not 100% clear.

Metadata.librettists

Gets a tuple or sets an iterable of librettists for this work:

>>> md = metadata.Metadata(title='Madama Butterfly')
>>> md.librettists = ['Illica, Luigi', 'Giacosa, Giuseppe']
>>> md.librettists
('Illica, Luigi', 'Giacosa, Giuseppe')

Should be distinguished from lyricists etc.

Metadata.localeOfComposition

Get or set the locale of composition, or origin, of the work.

>>> md = metadata.Metadata(popularTitle='Eroica')
>>> md.localeOfComposition = 'Paris, France'
>>> md.localeOfComposition
'Paris, France'

Metadata.lyricist

Gets or sets a single lyricist for this work:

>>> md = metadata.Metadata(title='Girlfriend')
>>> md.lyricist = 'Keys, Alicia'

To preserve continuity with Humdrum, library catalogues, etc., lyricists should be distinguished from librettists etc., but sometimes the line is not 100% clear:

>>> md = metadata.Metadata(title='West Side Story')
>>> md.lyricist = 'Sondheim, Stephen'
>>> md.lyricist
'Sondheim, Stephen'

Metadata.lyricists

Gets a tuple or sets an iterable of lyricists for this work:

>>> md = metadata.Metadata(title='Rumors')
>>> md.lyricists = ['Buckingham, Lindsey', 'McVie, Christine', 'Nicks, Stevie']
>>> md.lyricists
('Buckingham, Lindsey', 'McVie, Christine', 'Nicks, Stevie')

Should be distinguished from librettists etc.

Metadata.movementName

Get or set the movement title.

>>> md = metadata.Metadata()
>>> md.movementName = 'Vivace'
>>> md.movementName
'Vivace'

Note that a number of pieces from various MusicXML datasets have the piece title as the movement title. For instance, the Bach Chorales, since they are technically movements of larger cantatas.

Metadata.movementNumber

Get or set the movement number as a string (or None)

>>> md = metadata.Metadata(title='Ode to Joy')
>>> md.movementNumber = 4

Note that movement numbers are always returned as strings! This may change in the future.

>>> md.movementNumber
'4'

Metadata.number

Get or set the number of the work within a collection of pieces, as a string. (for instance, the number within a collection of ABC files)

>>> md = metadata.Metadata()
>>> md.number = '4'

Note that numbers are always returned as strings! This may change in the future.

>>> md.number
'4'

However, it is acceptable to set it as an int:

>>> md.number = 2
>>> md.number
'2'

Metadata.opusNumber

Get or set the opus number.

>>> md = metadata.Metadata()
>>> md.opusNumber = 56

Note that opusNumbers are always returned as strings! This may change in the future, however, it is less likely to change than .number or .movementNumber since Opus numbers such as 18a are common.

>>> md.opusNumber
'56'

There is no enforcement that only numbers actually called “opus” are used, and it could be used for other catalogue numbers.

>>> md.opusNumber = 'K.622'

Metadata.title

Get the title of the work.

>>> md = metadata.Metadata(title='Third Symphony')
>>> md.title
'Third Symphony'

>>> md = metadata.Metadata(popularTitle='Eroica')
>>> md.title is None
True

Read/write properties inherited from Music21Object:

activeSite derivation duration editorial

id offset priority

quarterLength seconds style

Metadata methods

Metadata.__getitem__(key: str) → Tuple[DatePrimitive | Text | Contributor | Copyright | int, ...]

“Dictionary key” access for all standard uniqueNames and standard keys of the form ‘namespace:name’.

These always return t.Tuple[ValueType, …], which may be empty.

If key is not a standard uniqueName or standard ‘namespace:name’, then KeyError is raised.

>>> md = metadata.Metadata()
>>> md['average duration']
Traceback (most recent call last):
KeyError: "Name='average duration' is not a standard metadata name...

Example: setting, then getting (dictionary style) a single value. Note that it must be set as a single element list/tuple, and is always returned as a single element tuple.

>>> md['description'] = [
...     metadata.Text('For the coronation of Catherine the Great.', language='en')
... ]
>>> descs = md['description']
>>> descs
(<music21.metadata.primitives.Text For the coronation of Catherine the Great.>,)

A second description can also be added.

>>> md.add('description', 'In five sections, unique for its time.')
>>> descs = md['description']
>>> isinstance(descs, tuple)
True
>>> len(descs)
2
>>> descs
(<music21.metadata.primitives.Text For the coronation of Catherine the Great.>,
 <music21.metadata.primitives.Text In five sections, unique for its time.>)
>>> descs[0].language
'en'
>>> descs[1].language is None
True

Metadata.add(name: str, value: Any | Iterable[Any])

Adds a single item or multiple items with this name, leaving any existing items with this name in place.

The name can be the item’s uniqueName or ‘namespace:name’. If it is not the uniqueName or namespaceName of one of the standard metadata properties, KeyError will be raised.

>>> md = metadata.Metadata()
>>> md.add('average duration', '180 minutes')
Traceback (most recent call last):
KeyError: "Name='average duration' is not a standard metadata name...

Example of adding a composer and two titles:

>>> md.add('composer', 'Houcine Slaoui')
>>> md['composer']
(<music21.metadata.primitives.Contributor composer:Houcine Slaoui>,)

>>> md.add('title', metadata.Text('الماريكان', language='ar'))
>>> md.add('title', metadata.Text('The Americans',  language='en'))
>>> titles = md['title']
>>> titles
(<music21.metadata.primitives.Text الماريكان>,
 <music21.metadata.primitives.Text The Americans>)
>>> titles[0].language
'ar'
>>> titles[1].language
'en'

If you do in fact want to overwrite any existing items with this name, you can use dictionary-style or attribute-style setting instead. See __setitem__() and __setattr__() for details.

Metadata.addContributor(c: Contributor)

Assign a Contributor object to this Metadata.

>>> md = metadata.Metadata(title='Gaelic Symphony')
>>> c = metadata.Contributor()
>>> c.name = 'Beach, Amy'
>>> c.role = 'composer'
>>> md.addContributor(c)
>>> md.composer
'Beach, Amy'

Add maiden name as an alternative composer name:

>>> c_alt = metadata.Contributor()
>>> c_alt.name = 'Cheney, Amy Marcy'
>>> c_alt.role = 'composer'
>>> md.addContributor(c_alt)
>>> md.composers
('Beach, Amy', 'Cheney, Amy Marcy')

>>> md.search('Beach')
(True, 'composer')
>>> md.search('Cheney')
(True, 'composer')

Note that in this case, a “composerAlias” would probably be a more appropriate role than a second composer.

All contributor roles are searchable, even if they are not standard roles:

>>> dancer = metadata.Contributor()
>>> dancer.names = ['Merce Cunningham', 'Martha Graham']
>>> dancer.role = 'interpretive dancer'
>>> md.addContributor(dancer)
>>> md.search('Cunningham')
(True, 'interpretive dancer')

Metadata.addCustom(name: str, value: Any | Iterable[Any])

Adds any custom-named metadata items. The name can be free-form, or it can be a custom ‘namespace:name’.

addCustom takes a single object of any type, or a list/tuple of objects of any type. The object(s) will be converted to Text.

>>> md = metadata.Metadata()
>>> md.addCustom('measure with 2nd ending', 'measure 128')
>>> md.getCustom('measure with 2nd ending')
(<music21.metadata.primitives.Text measure 128>,)

An item list can also be added.

>>> md.addCustom('measure with 2nd ending', ['measure 192', 'measure 256'])
>>> measures = md.getCustom('measure with 2nd ending')

>>> isinstance(measures, tuple)
True
>>> len(measures)
3
>>> measures
(<music21.metadata.primitives.Text measure 128>,
 <music21.metadata.primitives.Text measure 192>,
 <music21.metadata.primitives.Text measure 256>)

Metadata.all(*, skipContributors: bool = False, skipNonContributors: bool = False, returnPrimitives: bool = False, returnSorted: bool = True) → Tuple[Tuple[str, Any], ...]

Returns the values stored in this metadata as a Tuple of (uniqueName, value) pairs. There are four bool options. The three that are new in v8 (skipNonContributors, returnPrimitives, returnSorted) are defaulted to behave like v7.

If skipContributors is True, only non-contributor metadata will be returned. If skipNonContributors is True, only contributor metadata will be returned. If both of these are True, the returned Tuple will be empty. If returnPrimitives is False (default), values are all converted to str. If returnPrimitives is True, the values will retain their original ValueType (e.g. Text, Contributor, Copyright, etc). If returnSorted is False, the returned Tuple will not be sorted by uniqueName (the default behavior is to sort).

Note that we cannot properly type-hint the return value, since derived classes (such as RichMetadata) are allowed to return their own typed values that might not be str or ValueType.

>>> c = corpus.parse('corelli/opus3no1/1grave')
>>> c.metadata.all()
(('arranger', 'Michael Scott Cuthbert'),
 ('composer', 'Arcangelo Corelli'),
 ('copyright', '© 2014, Creative Commons License (CC-BY)'),
 ('fileFormat', 'musicxml'),
 ('filePath', '...corpus/corelli/opus3no1/1grave.xml'),
 ('movementName', 'Sonata da Chiesa, No. I (opus 3, no. 1)'),
 ('software', 'Dolet...'),
 ('software', 'Finale...'),
 ('software', 'music21 v...'))

>>> c.metadata.date = metadata.DateRelative('1689', 'onOrBefore')
>>> c.metadata.localeOfComposition = 'Rome'
>>> c.metadata.all(skipContributors=True)
(('copyright', '© 2014, Creative Commons License (CC-BY)'),
 ('dateCreated', '1689/--/-- or earlier'),
 ('fileFormat', 'musicxml'),
 ('filePath', '...corpus/corelli/opus3no1/1grave.xml'),
 ('localeOfComposition', 'Rome'),
 ('movementName', 'Sonata da Chiesa, No. I (opus 3, no. 1)'),
 ('software', 'Dolet...'),
 ('software', 'Finale...'),
 ('software', 'music21 v...'))

>>> c.metadata.all(returnPrimitives=True, returnSorted=False)
(('software', <music21.metadata.primitives.Text music21 v...>),
 ('software', <music21.metadata.primitives.Text Finale ...>),
 ('software', <music21.metadata.primitives.Text Dolet Light...>),
 ('movementName', <...Text Sonata da Chiesa, No. I (opus 3, no. 1)>),
 ('composer', <music21.metadata.primitives.Contributor composer:Arcangelo Corelli>),
 ...
 ('dateCreated', <music21.metadata.primitives.DateRelative 1689/--/-- or earlier>),
 ('localeOfComposition', <music21.metadata.primitives.Text Rome>))

>>> c.metadata.all(skipNonContributors=True, returnPrimitives=True, returnSorted=True)
(('arranger', <music21.metadata.primitives.Contributor arranger:Michael Scott Cuthbert>),
 ('composer', <music21.metadata.primitives.Contributor composer:Arcangelo Corelli>))

Metadata.getContributorsByRole(role: str | None) → Tuple[Contributor, ...]

Return a Contributor if defined for a provided role.

We allow role == None, since None is a valid custom contributor role.

>>> md = metadata.Metadata(title='Violin Concerto')

>>> c = metadata.Contributor()
>>> c.name = 'Price, Florence'
>>> c.role = 'composer'
>>> md.addContributor(c)
>>> cTuple = md.getContributorsByRole('composer')
>>> cTuple
(<music21.metadata.primitives.Contributor composer:Price, Florence>,)

>>> cTuple[0].name
'Price, Florence'

Some musicxml files have contributors with no role defined. To get these contributors, search for getContributorsByRole(None). N.B. upon output to MusicXML, music21 gives these contributors the generic role of “creator”

>>> c2 = metadata.Contributor()
>>> c2.name = 'Baron van Swieten'
>>> md.add('otherContributor', c2)
>>> noRoleTuple = md.getContributorsByRole(None)
>>> len(noRoleTuple)
1
>>> noRoleTuple[0].role is None
True
>>> noRoleTuple[0].name
'Baron van Swieten'

Metadata.getCustom(name: str) → Tuple[DatePrimitive | Text | Contributor | Copyright | int, ...]

Gets any custom-named metadata items. The name can be free-form, or it can be a custom ‘namespace:name’.

getCustom always returns t.Tuple[Text, …], which may be empty.

>>> md = metadata.Metadata()
>>> md.setCustom('measure with 2nd ending', 'measure 128')
>>> md.getCustom('measure with 2nd ending')
(<music21.metadata.primitives.Text measure 128>,)

A second item can also be added.

>>> md.addCustom('measure with 2nd ending', 'measure 192')
>>> measures = md.getCustom('measure with 2nd ending')

>>> isinstance(measures, tuple)
True
>>> len(measures)
2
>>> measures
(<music21.metadata.primitives.Text measure 128>,
 <music21.metadata.primitives.Text measure 192>)

static Metadata.isContributorUniqueName(uniqueName: str | None) → bool

Determines if a unique name is associated with a standard contributor property. Returns False if no such associated standard contributor property can be found.

We allow uniqueName == None, since None is a valid custom contributor role.

Example: ‘librettist’ and ‘otherContributor’ are unique names of standard contributors.

>>> metadata.Metadata.isContributorUniqueName('librettist')
True
>>> metadata.Metadata.isContributorUniqueName('otherContributor')
True

Example: ‘alternativeTitle’ is the unique name of a standard property, but it is not a contributor.

>>> metadata.Metadata.isContributorUniqueName('alternativeTitle')
False

Example: ‘average duration’ is not the unique name of a standard property.

>>> metadata.Metadata.isContributorUniqueName('average duration')
False

Metadata.isStandardName(name: str) → bool

Determines if name is either a ‘namespace:name’ or a ‘uniqueName’ associated with a standard property.

Returns False if no such associated standard property can be found.

>>> md = metadata.Metadata()
>>> md.isStandardName('librettist')
True

‘marcrel:LBT’ is the namespace name of ‘librettist’

>>> md.isStandardName('marcrel:LBT')
True

Some examples of non-standard (custom) names.

>>> md.isStandardName('average duration')
False
>>> md.isStandardName('soundtracker:SampleName')
False

static Metadata.namespaceNameToUniqueName(namespaceName: str) → str | None

Translates a standard property namespace name (‘namespace:name’) to that standard property’s uniqueName.

An example from the MARC Relators namespace: the unique name of ‘marcrel:LBT’ is ‘librettist’.

>>> metadata.Metadata.namespaceNameToUniqueName('marcrel:LBT')
'librettist'

Returns None if no such standard property exists.

>>> metadata.Metadata.namespaceNameToUniqueName('soundtracker:SampleName') is None
True

An example from the Dublin Core namespace: the unique name of ‘dcterms:alternative’ is ‘alternativeTitle’.

>>> metadata.Metadata.namespaceNameToUniqueName('dcterms:alternative')
'alternativeTitle'

Metadata.search(query=None, field=None, **keywords)

Search one or all fields with a query, given either as a string or a regular expression match.

>>> md = metadata.Metadata()
>>> md.composer = 'Joplin, Scott'
>>> md.title = 'Maple Leaf Rag'

>>> md.search(
...     'joplin',
...     field='composer',
...     )
(True, 'composer')

Note how the incomplete field name in the following example is still matched:

>>> md.search(
...     'joplin',
...     field='compos',
...     )
(True, 'composer')

These don’t work (Richard didn’t have the sense of rhythm to write this…)

>>> md.search(
...     'Wagner',
...     field='composer',
...     )
(False, None)

>>> md.search('Wagner')
(False, None)

>>> md.search('leaf')
(True, 'title')

>>> md.search(
...     'leaf',
...     field='composer',
...     )
(False, None)

>>> md.search(
...     'leaf',
...     field='title',
...     )
(True, 'title')

>>> md.search('leaf|entertainer')
(True, 'title')

>>> md.search('opl(.*)cott')
(True, 'composer')

New in v.4 – use a keyword argument to search that field directly:

>>> md.search(composer='Joplin')
(True, 'composer')

Metadata.setCustom(name: str, value: Any | Iterable[Any])

Sets any custom-named metadata items (deleting any existing such items). The name can be free-form, or it can be a custom ‘namespace:name’.

setCustom takes a single object of any type, or a list/tuple of objects of any type. The object(s) will be converted to Text.

>>> md = metadata.Metadata()
>>> md.setCustom('measure with 2nd ending', 'measure 128')
>>> md.getCustom('measure with 2nd ending')
(<music21.metadata.primitives.Text measure 128>,)

An item list can also be set.

>>> md.setCustom('measure with 2nd ending', ['measure 192', 'measure 256'])
>>> measures = md.getCustom('measure with 2nd ending')

>>> isinstance(measures, tuple)
True
>>> len(measures)
2
>>> measures
(<music21.metadata.primitives.Text measure 192>,
 <music21.metadata.primitives.Text measure 256>)

Metadata.setWorkId(idStr, value)

static Metadata.uniqueNameToNamespaceName(uniqueName: str) → str | None

Translates a unique name to the associated standard property’s namespace name (i.e. the property’s name in the form ‘namespace:name’).

An example from the MARC Relators namespace: the namespace name of ‘librettist’ is ‘marcrel:LBT’.

>>> metadata.Metadata.uniqueNameToNamespaceName('librettist')
'marcrel:LBT'

Returns None if no such associated standard property can be found.

>>> metadata.Metadata.uniqueNameToNamespaceName('average duration') is None
True

An example from the Dublin Core namespace: the namespace name of ‘alternativeTitle’ is ‘dcterms:alternative’.

>>> metadata.Metadata.uniqueNameToNamespaceName('alternativeTitle')
'dcterms:alternative'

Methods inherited from Music21Object:

clearCache() containerHierarchy() contextSites() getAllContextsByClass() getContextByClass() getOffsetBySite() getOffsetInHierarchy()

getSpannerSites() informSites() mergeAttributes() next() previous() purgeLocations() purgeOrphans()

setOffsetBySite() show() sortTuple() splitAtDurations() splitAtQuarterLength() splitByQuarterLengths() write()

Methods inherited from ProtoM21Object:

isClassOrSubclass()

Metadata instance variables

Instance variables inherited from Music21Object:

classSortOrder groups

isStream

sites

RichMetadata

class music21.metadata.RichMetadata(**keywords)

RichMetadata adds to Metadata information about the contents of the Score it is attached to. TimeSignature, KeySignature and related analytical is stored. RichMetadata are generally only created in the process of creating stored JSON metadata.

>>> richMetadata = metadata.RichMetadata(title='Concerto in F')
>>> richMetadata.title
'Concerto in F'

>>> richMetadata.keySignatureFirst = key.KeySignature(-1)
>>> 'keySignatureFirst' in richMetadata.additionalRichMetadataAttributes
True

RichMetadata objects contain all the usual Metadata items, plus some observed musical information analyzed from the score. Here is a list of what information is added:

>>> richMetadata.additionalRichMetadataAttributes
('ambitus', 'keySignatureFirst', 'keySignatures', 'noteCount', 'numberOfParts',
 'pitchHighest', 'pitchLowest', 'quarterLength', 'sourcePath', 'tempoFirst',
 'tempos', 'timeSignatureFirst', 'timeSignatures')

RichMetadata bases

• Metadata

• Music21Object

• ProtoM21Object

RichMetadata read-only properties

Read-only properties inherited from Metadata:

bestTitle

contributors

software

Read-only properties inherited from Music21Object:

beat beatDuration beatStr

beatStrength hasEditorialInformation

hasStyleInformation measureNumber

Read-only properties inherited from ProtoM21Object:

classSet

classes

RichMetadata read/write properties

Read/write properties inherited from Metadata:

alternativeTitle composer composers copyright date dateCreated fileFormat

fileNumber filePath librettist librettists localeOfComposition lyricist

lyricists movementName movementNumber number opusNumber title

Read/write properties inherited from Music21Object:

activeSite derivation duration editorial

id offset priority

quarterLength seconds style

RichMetadata methods

RichMetadata.all(*, skipContributors: bool = False, skipNonContributors: bool = False, returnPrimitives: bool = False, returnSorted: bool = True) → Tuple[Tuple[str, Any], ...]

Returns all values stored in this RichMetadata as a Tuple of Tuples. Each individual Metadata Tuple is (uniqueName, value) and each additional RichMetadata tuple is (name, richAttributeValue).

>>> rmd = metadata.RichMetadata()
>>> c = corpus.parse('corelli/opus3no1/1grave')
>>> rmd.merge(c.metadata)
>>> rmd.update(c)
>>> rmd.all()
(('ambitus',
    AmbitusShort(semitones=48, diatonic='P1', pitchLowest='C2', pitchHighest='C6')),
 ('arranger', 'Michael Scott Cuthbert'),
 ('composer', 'Arcangelo Corelli'),
 ...
 ('sourcePath', 'corelli/opus3no1/1grave.xml'),
 ('tempoFirst', None), ('tempos', []),
 ('timeSignatureFirst', '4/4'),
 ('timeSignatures', ['4/4']))

>>> rmd.dateCreated = metadata.DateRelative('1689', 'onOrBefore')
>>> rmd.localeOfComposition = 'Rome'
>>> rmd.all(skipContributors=True)
(('ambitus',
    AmbitusShort(semitones=48, diatonic='P1', pitchLowest='C2', pitchHighest='C6')),
 ('copyright', '© 2014, Creative Commons License (CC-BY)'),
 ('dateCreated', '1689/--/-- or earlier'),
 ('fileFormat', 'musicxml'),
 ...
 ('keySignatures', [-1]),
 ('localeOfComposition', 'Rome'),
 ('movementName', 'Sonata da Chiesa, No. I (opus 3, no. 1)'),
 ...
 ('timeSignatures', ['4/4']))

>>> rmd.all(returnPrimitives=True, returnSorted=False)
(('software', <music21.metadata.primitives.Text music21 ...>),
 ('software', <music21.metadata.primitives.Text Finale 2014 for Mac>),
 ('software', <music21.metadata.primitives.Text Dolet Light for Finale 2014>),
 ('movementName', <...Text Sonata da Chiesa, No. I (opus 3, no. 1)>),
 ('composer', <music21.metadata.primitives.Contributor composer:Arcangelo Corelli>),
 ...
 ('timeSignatures', ['4/4']))

>>> rmd.all(skipNonContributors=True, returnPrimitives=True, returnSorted=True)
(('arranger', <music21.metadata.primitives.Contributor arranger:Michael Scott Cuthbert>),
 ('composer', <music21.metadata.primitives.Contributor composer:Arcangelo Corelli>))

RichMetadata.getSourcePath(streamObj)

Get a string of the path after the corpus for the piece…useful for searching on corpus items without proper composer data…

>>> rmd = metadata.RichMetadata()
>>> b = corpus.parse('bwv66.6')
>>> rmd.getSourcePath(b)
'bach/bwv66.6.mxl'

RichMetadata.merge(other, favorSelf=False)

Given another Metadata or RichMetadata object, combine all attributes and return a new object.

>>> md = metadata.Metadata(title='Concerto in F')
>>> md.title
'Concerto in F'

>>> richMetadata = metadata.RichMetadata()
>>> richMetadata.merge(md)
>>> richMetadata.title
'Concerto in F'

RichMetadata.update(streamObj)

Given a Stream object, update attributes with stored objects.

>>> rmd = metadata.RichMetadata()
>>> rmd.keySignatureFirst is None
True
>>> rmd.sourcePath
''

>>> b = corpus.parse('bwv66.6')
>>> rmd.update(b)
>>> rmd.keySignatureFirst
3
>>> rmd.sourcePath
'bach/bwv66.6.mxl'
>>> rmd.numberOfParts
4

Methods inherited from Metadata:

__getitem__() add() addContributor() addCustom() getContributorsByRole()

getCustom() isContributorUniqueName() isStandardName() namespaceNameToUniqueName()

search() setCustom() setWorkId() uniqueNameToNamespaceName()

Methods inherited from Music21Object:

clearCache() containerHierarchy() contextSites() getAllContextsByClass() getContextByClass() getOffsetBySite() getOffsetInHierarchy()

getSpannerSites() informSites() mergeAttributes() next() previous() purgeLocations() purgeOrphans()

setOffsetBySite() show() sortTuple() splitAtDurations() splitAtQuarterLength() splitByQuarterLengths() write()

Methods inherited from ProtoM21Object:

isClassOrSubclass()

RichMetadata instance variables

Instance variables inherited from Music21Object:

classSortOrder groups

isStream

sites