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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.

>>> from music21 import *
>>> s = stream.Stream()
>>> s.append(note.Note())
>>> s.insert(metadata.Metadata())
>>> s.metadata.title = 'title'
>>> s.metadata.composer = 'composer'
>>> s.show()
_images/moduleMetadata-01.png
music21.metadata.abbreviationToRole(value)

Get ROLE_ABBREVIATIONS as string-like attributes, used for Contributors.

>>> abbreviationToRole('com')
'composer'
>>> abbreviationToRole('lib')
'librettist'
>>> for id in ROLE_ABBREVIATIONS:
...    post = abbreviationToRole(id)
music21.metadata.abbreviationToWorkId(value)

Get work id abbreviations.

>>> abbreviationToWorkId('otl')
'title'
>>> for id in WORK_ID_ABBREVIATIONS:
...    post = abbreviationToWorkId(id)
music21.metadata.errorToSymbol(value)

Convert an error string (appoximate, uncertain) into a symbol.

>>> errorToSymbol('approximate')
'~'
>>> errorToSymbol('uncertain')
'?'
music21.metadata.roleToAbbreviation(value)

Get a role id from a string representation.

>>> roleToAbbreviation('composer')
'com'
>>> for n in ROLES:
...     post = roleToAbbreviation(n)
music21.metadata.workIdToAbbreviation(value)

Get a role id from a string representation.

>>> workIdToAbbreviation('localeOfComposition')
'opc'
>>> for n in WORK_IDS:
...     post = workIdToAbbreviation(n)

Text

class music21.metadata.Text(data=, language=None)

One unit of text data: a title, a name, or some other text data. Store the string and a language name or code. This object can be used and/or subclassed for a variety for of text storage.

>>> td = Text('concerto in d', 'en')
>>> str(td)
'concerto in d'

Text properties

language

Set the language of the Text stored within.

>>> t = Text('my text')
>>> t.language = 'en'
>>> t.language
'en'

Date

class music21.metadata.Date(*args, **keywords)

A single date value, specified by year, month, day, hour, minute, and second. Note that this class has been created, instead of using Python’s datetime, to provide greater flexibility for processing unconventional dates, ancient dates, dates with error, and date ranges. The datetime property can be used to retrieve a datetime object when necessary. Additionally, each value can be specified as uncertain or approximate; if None, assumed to be certain. Data objects are fundamental components of DateSingle and related subclasses that represent single dates and date ranges.

>>> a = Date(year=1843, yearError='approximate')
>>> a.year
1843
>>> a.yearError
'approximate'
>>> a = Date(year='1843?')
>>> a.yearError
'uncertain'

Date attributes

Attributes without Documentation: attrStrFormat, minuteError, monthError, hour, hourError, dayError, attrNames, month, second, secondError, yearError, year, day, minute

Date properties

datetime

Return a datetime object representation.

>>> a = Date(year=1843, month=3, day=3)
>>> a.datetime
datetime.datetime(1843, 3, 3, 0, 0)
hasError

Return True if any data points have error defined.

>>> a = Date(year=1843, month=3, day=3, dayError='approximate')
>>> a.hasError
True
>>> b = Date(year=1843, month=3, day=3, minute=3)
>>> b.hasError
False
hasTime

Return True if any time elements are defined.

>>> a = Date(year=1843, month=3, day=3)
>>> a.hasTime
False
>>> b = Date(year=1843, month=3, day=3, minute=3)
>>> b.hasTime
True

Date methods

load(value)

Load values by string, datetime object, or Date object.

>>> a = Date(year=1843, month=3, day=3)
>>> b = Date()
>>> b.load(a)
>>> b.year
1843
loadDatetime(dt)

Load time data from a datetime object.

>>> import datetime
>>> dt = datetime.datetime(2005, 02, 01)
>>> dt
datetime.datetime(2005, 2, 1, 0, 0)
>>> a = Date()
>>> a.loadDatetime(dt)
>>> str(a)
'2005/02/01'
loadOther(other)

Load values based on another Date object:

>>> a = Date(year=1843, month=3, day=3)
>>> b = Date()
>>> b.loadOther(a)
>>> b.year
1843
loadStr(str)

Load a string date representation. Assume year/month/day/hour:minute:second

>>> from music21 import *
>>> d = metadata.Date()
>>> d.loadStr('3030?/12~/?4')
>>> d.month, d.monthError
(12, 'approximate')
>>> d.year, d.yearError
(3030, 'uncertain')
>>> d.month, d.monthError
(12, 'approximate')
>>> d.day, d.dayError
(4, 'uncertain')
>>> d = metadata.Date()
>>> d.loadStr('1834/12/4/4:50:32')
>>> d.minute, d.second
(50, 32)

DateSingle

class music21.metadata.DateSingle(data=, relevance=certain)

Store a date, either as certain, approximate, or uncertain relevance. The relevance attribute is limited within each DateSingle subclass depending on the design of the class. Alternative relevance types should be configured as other DateSingle subclasses.

>>> dd = DateSingle('2009/12/31', 'approximate')
>>> str(dd)
'2009/12/31'
>>> dd.relevance
'approximate'
>>> dd = DateSingle('1805/3/12', 'uncertain')
>>> str(dd)
'1805/03/12'

DateSingle attributes

Attributes without Documentation: isSingle

DateSingle properties

datetime

Return a datetime object representation.

>>> d = Date(year=1843, month=3, day=3)
>>> ds = DateSingle(d)
>>> ds.datetime
datetime.datetime(1843, 3, 3, 0, 0)
relevance
No documentation.

DateRelative

class music21.metadata.DateRelative(data=, relevance=after)

Store a relative date, sometime prior or sometime after

>>> dd = DateRelative('2009/12/31', 'prior')
>>> str(dd)
'2009/12/31'
>>> dd = DateRelative('2009/12/31', 'certain')
Traceback (most recent call last):
MetadataException: relevance value is not supported by this object: certain

inherits from: DateSingle

DateBetween

class music21.metadata.DateBetween(data=[], relevance=between)

Store a relative date, sometime between two dates

>>> dd = DateBetween(['2009/12/31', '2010/1/28'])
>>> str(dd)
'2009/12/31 to 2010/01/28'
>>> dd = DateBetween(['2009/12/31', '2010/1/28'], 'certain')
Traceback (most recent call last):
MetadataException: relevance value is not supported by this object: certain

inherits from: DateSingle

DateSelection

class music21.metadata.DateSelection(data=, relevance=or)

Store a selection of dates, or a collection of dates that might all be possible

>>> dd = DateSelection(['2009/12/31', '2010/1/28', '1894/1/28'], 'or')
>>> str(dd)
'2009/12/31 or 2010/01/28 or 1894/01/28'
>>> dd = DateSelection(['2009/12/31', '2010/1/28'], 'certain')
Traceback (most recent call last):
MetadataException: relevance value is not supported by this object: certain

inherits from: DateSingle

Contributor

class music21.metadata.Contributor(*args, **keywords)

A person that contributed to a work. Can be a composer, lyricist, arranger, or other type of contributor. In MusicXML, these are “creator” elements.

>>> td = Contributor(role='composer', name='Chopin, Fryderyk')
>>> td.role
'composer'
>>> td.name
'Chopin, Fryderyk'
>>> td.relevance
'contributor'

Contributor attributes

Attributes without Documentation: relevance

Contributor properties

mx

Return a mxCreator object based on this object.

>>> from music21 import *
>>> md = metadata.Metadata()
>>> md.composer = 'frank'
>>> mxCreator = md._contributors[0].mx
>>> mxCreator.get('charData')
'frank'
>>> mxCreator.get('type')
'composer'
name

Returns the text name, or the first of many names entered.

>>> td = Contributor(role='composer', names=['Chopin, Fryderyk', 'Chopin, Frederick'])
>>> td.name
'Chopin, Fryderyk'
>>> td.names
['Chopin, Fryderyk', 'Chopin, Frederick']
names

Returns all names in a list.

>>> td = Contributor(role='composer', names=['Chopin, Fryderyk', 'Chopin, Frederick'])
>>> td.names
['Chopin, Fryderyk', 'Chopin, Frederick']
role

The role is what part this Contributor plays in the work. Both full roll strings and roll abbreviations may be used.

>>> td = Contributor()
>>> td.role = 'composer'
>>> td.role
'composer'
>>> td.role = 'lor'
>>> td.role
'orchestrator'

Contributor methods

age()

Calculate the age of the Contributor, returning a datetime.timedelta object.

>>> a = Contributor(name='Beethoven, Ludwig van', role='composer', birth='1770/12/17', death='1827/3/26')
>>> a.role
'composer'
>>> a.age()
datetime.timedelta(20552)
>>> str(a.age())
'20552 days, 0:00:00'
>>> a.age().days / 365
56

Metadata

class music21.metadata.Metadata(*args, **keywords)

Metadata represent data for a work or fragment, including title, composer, dates, and other relevant information. Metadata is a Music21Object subclass, meaing 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.

>>> md = Metadata(title='Concerto in F')
>>> md.title
'Concerto in F'
>>> md = Metadata(otl='Concerto in F') # can use abbreviations
>>> md.title
'Concerto in F'
>>> md.setWorkId('otl', 'Rhapsody in Blue')
>>> md.otl
'Rhapsody in Blue'
>>> md.title
'Rhapsody in Blue'

inherits from: Music21Object

Metadata attributes

Attributes inherited from Music21Object: classSortOrder, id, groups

Metadata properties

composer

Get or set the composer of this work. More than one composer may be specified. The composer attribute does not live in Metadata, but creates a Contributor object in the Metadata object.

>>> md = Metadata(title='Third Symphony', popularTitle='Eroica', composer='Beethoven, Ludwig van')
>>> md.composer
'Beethoven, Ludwig van'
composers
Get a list of all Contributor objects defined as composer of this work.
movementName
Get or set the movement title.
movementNumber
Get or set the movement number.
mx
Return a mxScore object, to be merged or used in final musicxml output
number
Get or set the number of the work.
opusNumber
Get or set the opus number.
title

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

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

Properties inherited from Music21Object: duration, offset, parent, priority

Metadata methods

addContributor(c)

Assign a Contributor object to this Metadata.

>>> md = Metadata(title='Third Symphony')
>>> c = Contributor()
>>> c.name = 'Beethoven, Ludwig van'
>>> c.role = 'composer'
>>> md.addContributor(c)
>>> md.composer
'Beethoven, Ludwig van'
>>> md.composer = 'frank'
>>> md.composers
['Beethoven, Ludwig van', 'frank']
getContributorsByRole(value)

Return a Contributor if defined for a provided role.

>>> md = Metadata(title='Third Symphony')
>>> c = Contributor()
>>> c.name = 'Beethoven, Ludwig van'
>>> c.role = 'composer'
>>> md.addContributor(c)
>>> cList = md.getContributorsByRole('composer')
>>> cList[0].name
'Beethoven, Ludwig van'
setWorkId(idStr, value)

Directly set a workd id, given either as a full string name or as a three character abbreviation.

>>> md = Metadata(title='Quartet')
>>> md.title
'Quartet'
>>> md.setWorkId('otl', 'Trio')
>>> md.title
'Trio'
>>> md.setWorkId('sdf', None)
Traceback (most recent call last):
MetadataException: no work id available with id: sdf

Methods inherited from Music21Object: searchParentByAttr(), getContextAttr(), setContextAttr(), addContext(), addLocation(), addLocationAndParent(), freezeIds(), getContextByClass(), getOffsetBySite(), getSiteIds(), getSites(), hasContext(), isClass(), purgeLocations(), removeLocationBySite(), removeLocationBySiteId(), setOffsetBySite(), show(), unfreezeIds(), unwrapWeakref(), wrapWeakref(), write()

Creator

class music21.metadata.Creator(*args, **keywords)

A person that created a work. Can be a composer, lyricist, arranger, or other type of contributor. In MusicXML, these are “creator” elements.

>>> td = Creator(role='composer', name='Chopin, Fryderyk')
>>> td.role
'composer'
>>> td.name
'Chopin, Fryderyk'
>>> td.relevance
'creator'

inherits from: Contributor

Imprint

class music21.metadata.Imprint(*args, **keywords)
An object representation of imprint, or publication.