MObj¶

class maelzel.core.mobj.MObj(dur, offset=None, label='', parent=None, properties=None, symbols=None)[source]¶

Bases: ABC

This is the base class for all core objects.

This is an abstract class. It should not be instantiated by itself. A MObj can display itself via show() and play itself via play(). Any MObj has a duration (dur) and a time offset (offset). The offset can be left as None, indicating that it is not explicitely set, in which case it will be calculated from the context. In the case of events or chains, which can be contained within other objects, the offset depends on the previous objects. The resolved (implicit) offset can be queried via MObj.relOffset(). This offset is relative to the parent, or an absolute offset if the object has no parent. The absolute offset can be queried via MObj.absOffset().

A MObj can customize its playback via setPlay(). The playback attributes can be accessed through the playargs attribute

Elements purely related to notation (text annotations, articulations, etc) are added to a MObj through the addSymbol() and can be accessed through the MObj.symbols attribute. A symbol is an attribute or notation element (like color, size or an attached text expression) which has meaning only in the realm of graphical representation.

Parameters:

dur (Fraction) – the duration of this object, in quarternotes
offset (Optional[Fraction]) – the (optional) time offset of this object, in quarternotes
label (str) – a string label to identify this object, if necessary

Attributes Summary

`dur`	The duration of this object, in quarternotes
`end`	The end time of this object.
`label`	a label can be used to identify an object within a group of objects
`offset`	Optional offset, in quarternotes.
`parent`	The parent of this object.
`playargs`	playargs are set via `setPlay()` and are used to customize playback (instr, gain, …).
`properties`	User-defined properties as a dict (None by default).
`symbols`	A list of all symbols added via `addSymbol()` (None by default)

Methods Summary

`absOffset`()	Returns the absolute offset of this object in quarternotes
`addSymbol`(args, *kws)	rtype: `Self`
`addText`(text[, placement, italic, weight, ...])	Add a text annotation to this object
`clone`(**kws)	Clone this object, changing parameters if needed
`copy`()	Returns a copy of this object
`dump`([indents, forcetext])	Prints all relevant information about this object
`durSecs`()	Returns the duration in seconds according to the active score
`events`([instr, delay, args, gain, chan, ...])	Returns the SynthEvents needed to play this object
`getPlay`(key[, default, recursive])	Get a playback attribute previously set via `MObj.setPlay()`
`getProperty`(key[, default])	Get a property of this objects
`getSymbol`(classname)	Get a symbol of a given class, if present
`invertPitch`(pivot)	Invert the pitch of this object
`isRest`()	Is this object a Rest?
`meanPitch`()	The mean pitch of this object
`parentAbsOffset`()	The absolute offset of the parent
`pitchRange`()	The pitch range of this object, if applicable
`pitchTransform`(pitchmap)	Apply a pitch-transform to this object, returns a copy
`play`([instr, delay, args, gain, chan, ...])	Plays this object.
`plot`(**kws)	rtype: `Axes`
`quantizePitch`([step])	Returns a new object, with pitch rounded to step
`quantizedScore`([scorestruct, config, ...])	Returns a QuantizedScore representing this object
`rec`([outfile, sr, verbose, wait, nchnls, ...])	Record the output of .play as a soundfile
`relOffset`()	Resolve the offset of this object, relative to its parent
`remap`(deststruct[, sourcestruct])	Remap times (offset, dur) from source scorestruct to destination scorestruct
`render`([backend, renderoptions, ...])	Renders this object as notation
`resolveEnd`()	Returns the resolved end of this object, relative to its parent
`scorestruct`([resolve])	Returns the ScoreStruct active for this obj or its parent (recursively)
`scoringEvents`([groupid, config, parentOffset])	Returns its notated form as scoring.Notations
`scoringParts`([config])	Returns this object as a list of scoring UnquantizedParts.
`setPlay`(**kws)	Set any playback attributes, returns self
`setProperty`(key, value)	Set a property, returns self
`show`([fmt, external, backend, scorestruct, ...])	Show this as notation.
`timeRangeSecs`([parentOffset, scorestruct])	The absolute time range, in seconds
`timeScale`(factor[, offset])	Create a copy with modified timing by applying a linear transformation
`timeShift`(timeoffset)	Return a copy of this object with an added offset
`timeShiftInPlace`(timeoffset)	Shift the time of this by the given offset (inplace)
`timeTransform`(timemap[, inplace])	Apply a time-transform to this object
`transpose`(interval)	Transpose this object by the given interval
`transposeByRatio`(ratio)	Transpose this by a given frequency ratio, if applicable
`unquantizedScore`([title])	Create a maelzel.scoring.UnquantizedScore from this object
`withExplicitOffset`([forcecopy])	Copy of self with explicit times
`write`(outfile[, backend, resolution])	Export to multiple formats

Attributes Documentation

dur¶: The duration of this object, in quarternotes

end¶

The end time of this object.

Will be None if this object has no explicit offset. Use :meth:`

label: str¶: a label can be used to identify an object within a group of objects

offset: Fraction | None¶

Optional offset, in quarternotes. Specifies the start time relative to its parent

It can be None, which indicates that within a container this object would start after the previous object. For an object without a parent, the offset is an absolute offset.

parent¶

The parent of this object.

This attribute is set by the parent when an object is added to it. For example, when adding a Note to a Chain, the Chain is set as the parent of the Note. This enables the Note to query information about the parent, like its absolute position or if a score structure has been set upstream

playargs: PlayArgs | None¶: playargs are set via setPlay() and are used to customize playback (instr, gain, …). None by default

properties: dict[str, Any] | None¶: User-defined properties as a dict (None by default). Set them via setProperty()

symbols: list[Symbol] | None¶: A list of all symbols added via addSymbol() (None by default)

Methods Documentation

absOffset()[source]¶

Returns the absolute offset of this object in quarternotes

If this object is embedded (has a parent) in a container, its absolute offset depends on the offset of its parent, recursively. If the object has no parent then the absolute offset is just the resolved offset

Return type:: Fraction
Returns:: the absolute start position of this object

addSymbol(*args, **kws)[source]¶

Return type:: Self

addText(text, placement='above', italic=False, weight='normal', fontsize=None, fontfamily='', box='')[source]¶

Add a text annotation to this object

This is a shortcut to self.addSymbol(symbols.Text(...)). Use that for in-depth customization.

Parameters:

text (str) – the text annotation
placement – where to place the annotation (‘above’, ‘below’)
italic – if True, use italic as font style
weight – ‘normal’ or ‘bold’
fontsize (Optional[int]) – the size of the annotation
fontfamily – the font family to use. It is probably best to leave this unset
box – the enclosure shape, or ‘’ for no box around the text. Possible shapes are ‘square’, ‘circle’, ‘rounded’

Return type:

Self

Returns:

self

clone(**kws)[source]¶

Clone this object, changing parameters if needed

Parameters:: **kws – any keywords passed to the constructor
Return type:: Self
Returns:: a clone of this object, with the given arguments changed

Example:

>>> from maelzel.core import *
>>> a = Note("C4+", dur=1)
>>> b = a.clone(dur=0.5)

copy()[source]¶

Returns a copy of this object

Return type:: Self

dump(indents=0, forcetext=False)[source]¶

Prints all relevant information about this object

Parameters:

indents – number of indents
forcetext – if True, force text output via print instead of html even when running inside jupyter

durSecs()[source]¶

Returns the duration in seconds according to the active score

Return type:: Fraction
Returns:: the duration of self in seconds

events(instr=None, delay=None, args=None, gain=None, chan=None, pitchinterpol=None, fade=None, fadeshape=None, position=None, skip=None, end=None, sustain=None, workspace=None, transpose=0.0, **kwargs)[source]¶

Returns the SynthEvents needed to play this object

All these attributes here can be set previously via playargs (or using setPlay())

Parameters:

gain (Optional[float]) – modifies the own amplitude for playback/recording (0-1)
delay (Optional[float]) – delay in seconds, added to the start of the object As opposed to the .offset attribute of each object, which is defined in quarternotes, the delay is always in seconds
instr (Optional[str]) – which instrument to use (see defPreset, definedPresets). Use “?” to select from a list of defined presets.
chan (Optional[int]) – the channel to output to. Channels start at 1
pitchinterpol (Optional[str]) – ‘linear’, ‘cos’, ‘freqlinear’, ‘freqcos’
fade (Union[float, tuple[float, float], None]) – fade duration in seconds, can be a tuple (fadein, fadeout)
fadeshape (Optional[str]) – ‘linear’ | ‘cos’
args (Optional[dict[str, float]]) – named arguments passed to the note. A dict {paramName: value}
position (Optional[float]) – the panning position (0=left, 1=right)
skip (Optional[float]) – start playback at the given offset (in quarternotes), relative to the start of the object. Allows to play a fragment of the object (NB: this trims the playback of the object. Use delay to offset the playback in time while keeping the playback time unmodified)
end (Optional[float]) – end time of playback, in quarternotes. Allows to play a fragment of the object by trimming the end of the playback
sustain (Optional[float]) – a time added to the playback events to facilitate overlapping/legato between notes, or to allow one-shot samples to play completely without being cropped.
workspace (Optional[Workspace]) – a Workspace. If given, overrides the current workspace. It’s scorestruct is used to determine the mapping between beat-time and real-time.
transpose (float) – an interval to transpose any pitch

Return type:

list[SynthEvent]

Returns:

A list of SynthEvents (see SynthEvent)

Example

>>> from maelzel.core import *
>>> n = Note(60, dur=1).setPlay(instr='piano')
>>> n.events(gain=0.5)
[SynthEvent(delay=0.000, gain=0.5, chan=1, fade=(0.02, 0.02), instr=piano)
 bps 0.000s:  60, 1.000000
     1.000s:  60, 1.000000]
>>> play(n.events(chan=2))

getPlay(key, default=None, recursive=True)[source]¶

Get a playback attribute previously set via MObj.setPlay()

Parameters:

key (str) – the key (see setPlay for possible keys)
default – the value to return if the given key has not been set
recursive – if True, search the given attribute up the parent chain

Returns:

either the value previously set, or default otherwise.

getProperty(key, default=None)[source]¶

Get a property of this objects

Any MObj can have multiple properties. A property is a key:value pair, where the key is a string and the value can be anything. Properties can be used to attach information to an object, to tag it in any way needed.

Properties are set via MObj.setProperty(). The MObj.properties attribute can be queries directly, but bear in mind that if no properties have been set, this attribute is ``None`` by default.

Parameters:

key (str) – the property to query
default – returned value if the property has not been set

Returns:

the value of the property, or the default value

See also

setProperty(), properties

getSymbol(classname)[source]¶

Get a symbol of a given class, if present

This is only supported for symbol classes which are exclusive (notehead, color, ornament, etc.). For symbols like ‘articulation’, which can be present multiple times, query the symbols attribute directly (NB: symbols might be None if no symbols have been set):

if note.symbols:
    articulations = [s for s in note.symbols
                     if s.name == 'articulation']

Parameters:: classname (str) – the class of the symbol. Possible values are ‘articulation’, ‘text’, ‘notehead’, ‘color’, ‘ornament’, ‘fermata’, ‘notatedpitch’. See XXX (TODO) for a complete list
Return type:: Symbol | None
Returns:: a symbol of the given class, or None

invertPitch(pivot)[source]¶

Invert the pitch of this object

Parameters:: pivot (Union[int, float, str]) – the point around which to invert pitches
Return type:: Self
Returns:: the inverted object

>>> from maelzel.core import *
>>> series = Chain("4Bb 4E 4F# 4Eb 4F 4A 5D 5C# 4G 4G# 4B 5C".split())
>>> inverted = series.invertPitch("4F#")
>>> print(" ".join(_.name.ljust(4) for _ in series))
... print(" ".join(_.name.ljust(4) for _ in inverted))
4A#  4E   4F#  4D#  4F   4A   5D   5C#  4G   4G#  4B   5C
4D   4G#  4F#  4A   4G   4D#  3A#  3B   4F   4E   4C#  4C
>>> Score([series, inverted])

../_images/dodecaphonic-series-1-inverted.png

isRest()[source]¶

Is this object a Rest?

Rests are used as separators between objects inside an Chain or a Track

Return type:: bool

meanPitch()[source]¶

The mean pitch of this object

Return type:: float | None
Returns:: The mean pitch of this object

parentAbsOffset()[source]¶

The absolute offset of the parent

Return type:: Fraction
Returns:: the absolute offset of the parent if this object has a parent, else 0

pitchRange()[source]¶

The pitch range of this object, if applicable

This is useful in order to assign this object to a proper Voice when distributing objects among voices

Return type:: tuple[float, float] | None
Returns:: either None or a tuple (lowest pitch, highest pitch)

pitchTransform(pitchmap)[source]¶

Apply a pitch-transform to this object, returns a copy

Parameters:: pitchmap (Callable[[float], float]) – a function mapping pitch to pitch
Return type:: Self
Returns:: the object after the transform

play(instr=None, delay=None, args=None, gain=None, chan=None, pitchinterpol=None, fade=None, fadeshape=None, position=None, skip=None, end=None, whenfinished=None, sustain=None, workspace=None, transpose=0, config=None, display=False, **kwargs)[source]¶

Plays this object.

Play is always asynchronous (to block, use some sleep funcion). By default, play() schedules this event to be renderer in realtime.

Note

To record events offline, see the example below

Parameters:

gain (Optional[float]) – modifies the own amplitude for playback/recording (0-1)
delay (Optional[float]) – delay in seconds, added to the start of the object As opposed to the .offset attribute of each object, which is defined in symbolic (beat) time, the delay is always in real (seconds) time
instr (Optional[str]) – which instrument to use (see defPreset, definedPresets). Use “?” to select from a list of defined presets.
chan (Optional[int]) – the channel to output to. Channels start at 1
pitchinterpol (Optional[str]) – ‘linear’, ‘cos’, ‘freqlinear’, ‘freqcos’
fade (Union[float, tuple[float, float], None]) – fade duration in seconds, can be a tuple (fadein, fadeout)
fadeshape (Optional[str]) – ‘linear’ | ‘cos’
args (Optional[dict[str, float]]) – arguments passed to the note. A dict {paramName: value}
position (Optional[float]) – the panning position (0=left, 1=right)
skip (Optional[float]) – amount of time (in quarternotes) to skip. Allows to play a fragment of the object (NB: this trims the playback of the object. Use delay to offset the playback in time while keeping the playback time unmodified)
end (Optional[float]) – end time of playback. Allows to play a fragment of the object by trimming the end of the playback
sustain (Optional[float]) – a time added to the playback events to facilitate overlapping/legato between notes, or to allow one-shot samples to play completely without being cropped.
workspace (Optional[Workspace]) – a Workspace. If given, overrides the current workspace. It’s scorestruct is used to to determine the mapping between beat-time and real-time.
transpose (float) – add a transposition interval to the pitch of this object
config (Optional[CoreConfig]) – if given, overrides the current config
whenfinished (Optional[Callable]) – function to be called when the playback is finished. Only applies to realtime rendering
display – if True and running inside Jupyter, display the resulting synth’s html

Return type:

SynthGroup

Returns:

A SynthGroup

See also

MObj.events
MObj.rec
render(),
play()

Example

Play a note

>>> from maelzel.core import *
>>> note = Note(60).play(gain=0.1, chan=2)

Play multiple objects synchronised

>>> play(
... Note(60, 1.5).events(gain=0.1, position=0.5)
... Chord("4E 4G", 2, start=1.2).events(instr='piano')
... )

Or using play as a context managger:

>>> with play():
...     Note(60, 1.5).play(gain=0.1, position=0.5)
...     Chord("4E 4G", 2, start=1.2).play(instr='piano')
...     ...

Render offline

>>> with render("out.wav", sr=44100) as r:
...     Note(60, 5).play(gain=0.1, chan=2)
...     Chord("4E 4G", 3).play(instr='piano')

plot(**kws)[source]¶

Return type:: Axes

quantizePitch(step=0.0)[source]¶

Returns a new object, with pitch rounded to step

Return type:: Self

quantizedScore(scorestruct=None, config=None, quantizationProfile=None, enharmonicOptions=None, nestedTuplets=None)[source]¶

Returns a QuantizedScore representing this object

Parameters:

scorestruct (Optional[ScoreStruct]) – if given it will override the scorestructure active for this object
config (Optional[CoreConfig]) – if given will override the active config
quantizationProfile (Union[str, QuantizationProfile, None]) – if given it is used to customize the quantization process. Otherwise, a profile is constructed based on the config. It is also possible to pass the name of a quantization preset (possible values: ‘lowest’, ‘low’, ‘medium’, ‘high’, ‘highest’, see maelzel.scoring.quant.QuantizationProfile.fromPreset())
enharmonicOptions (Optional[EnharmonicOptions]) – if given it is used to customize enharmonic respelling. Otherwise, the enharmonic options used for respelling are constructed based on the config
nestedTuplets (Optional[bool]) – if given, overloads the config value ‘quant.nestedTuplets’. This is used to disallow nested tuplets, mainly for rendering musicxml since there are some music editors (MuseScore, for example) which fail to import nested tuplets. This can be set at the config level as getConfig()['quant.nestedTuplets'] = False

Return type:

QuantizedScore

Returns:

a quantized score. To render such a quantized score as notation call its render() method

A QuantizedScore contains a list of QuantizedParts, which each consists of list of QuantizedMeasures. To access the recursive notation structure of each measure call its asTree() method

rec(outfile='', sr=None, verbose=None, wait=None, nchnls=None, instr=None, delay=None, args=None, gain=None, position=None, extratime=None, workspace=None, **kws)[source]¶

Record the output of .play as a soundfile

Parameters:

outfile – the outfile where sound will be recorded. Can be None, in which case a filename will be generated. Use ‘?’ to open a save dialog
sr (Optional[int]) – the sampling rate (config key: ‘rec.sr’)
wait (Optional[bool]) – if True, the operation blocks until recording is finishes (config ‘rec.block’)
nchnls (Optional[int]) – if given, use this as the number of channels to record.
gain (Optional[float]) – modifies the own amplitude for playback/recording (0-1)
delay (Optional[float]) – delay in seconds, added to the start of the object As opposed to the .start attribute of each object, which is defined in symbolic (beat) time, the delay is always in real (seconds) time
instr (Optional[str]) – which instrument to use (see defPreset, definedPresets). Use “?” to select from a list of defined presets.
args (Optional[dict[str, float]]) – named arguments passed to the note. A dict {paramName: value}
position (Optional[float]) – the panning position (0=left, 1=right)
workspace (Optional[Workspace]) – if given it overrides the active workspace
extratime (Optional[float]) – extratime added to the recording (config key: ‘rec.extratime’)
verbose (Optional[bool]) – if True, display synthesis output
**kws – any keyword passed to .play

Return type:

OfflineRenderer

Returns:

the offline renderer used. If no outfile was given it is possible to access the renderer soundfile via OfflineRenderer.lastOutfile()

Example

>>> from maelzel.core import *
>>> # a simple note
>>> chord = Chord("4C 4E 4G", dur=8).setPlay(gain=0.1, instr='piano')
>>> renderer = chord.rec(wait=True)
>>> renderer.lastOutfile()
'/home/testuser/.local/share/maelzel/recordings/tmpashdas.wav'

See also

OfflineRenderer

relOffset()[source]¶

Resolve the offset of this object, relative to its parent

If this object has no parent the offset is an absolute offset.

The .offset attribute holds the explicit offset. If this attribute is unset (None) this object might ask its parent to determine the offset based on the durations of any previous objects

Return type:: Fraction
Returns:: the offset, in quarter notes. If no explicit or implicit offset and the object has no parent it returns 0.

See also

MObj.absOffset()

remap(deststruct, sourcestruct=None)[source]¶

Remap times (offset, dur) from source scorestruct to destination scorestruct

The absolute time remains the same

Parameters:

deststruct (ScoreStruct) – the destination scorestruct
sourcestruct (Optional[ScoreStruct]) – the source scorestructure, or None to use the resolved scoresturct

Return type:

Self

Returns:

a clone of self remapped to the destination scorestruct

render(backend='', renderoptions=None, scorestruct=None, config=None, quantizationProfile=None)[source]¶

Renders this object as notation

First the object is quantized to abstract notation, then it is passed to the backend to render it for the specific format (lilypond, musicxml, …), which is then used to generate a document (pdf, png, …)

Parameters:

backend – the backend to use, one of ‘lilypond’, ‘musicxml’. If not given, defaults to the config key ‘show.backend’
renderoptions (Optional[RenderOptions]) – the render options to use. If not given, these are generated from the active config
scorestruct (Optional[ScoreStruct]) – if given, overrides the scorestruct set within the active Workspace and any scorestruct attached to this object
config (Optional[CoreConfig]) – if given, overrides the active config
quantizationProfile (Union[str, QuantizationProfile, None]) – if given, it is used to customize the quantization process and will override any config option related to quantization. A QuantizationProfile can be created from a config via maelzel.core.config.CoreConfig.makeQuantizationProfileFromPreset().

Return type:

Renderer

Returns:

a scoring.render.Renderer. This can be used to write the rendered structure to an image (png, pdf) or as a musicxml or lilypond file.

Example

>>> from maelzel.core import *
>>> voice = Voice(...)
# Render with the settings defined in the config
>>> voice.render()
# Customize the rendering process
>>> from maelzel.scoring.renderer import RenderOptions
>>> from maelzel.scoring.quant import QuantizationProfile
>>> quantprofile = QuantizationProfile.simple(
...     possibleDivisionsByTempo={80: []
...     })

resolveEnd()[source]¶

Returns the resolved end of this object, relative to its parent

An object’s offset can be explicit (set in the .offset attributes) or implicit, as calculated from the context of the parent. For example, inside a Chain, the offset of an event depends on the offsets and durations of the objects preceding it.

Note

To calculate the absolute end of an object, use obj.absOffset() + obj.resolveEnd

Return type:: Fraction
Returns:: the resolved end of this object, relative to its parent. If this object has no parent, the relative end and the absolute end are the same

See also

MObj.relOffset(), MObj.absOffset()

scorestruct(resolve=False)[source]¶

Returns the ScoreStruct active for this obj or its parent (recursively)

If this object has no parent None is returned. If resolve is True and this object has no associated scorestruct, the active scorestruct is returned

Parameters:: resolve – if True and this obj (or its parent, recursively) has no associated scorestruct, the active scorestruct is returned
Return type:: ScoreStruct | None
Returns:: the associated scorestruct or the active struct if resolve is True and this object has no associated struct (either directly or through its parent)

Example

>>> from maelzel.core import *
>>> n = Note("4C", 1)
>>> voice = Voice([n])
>>> score = Score([voice])
>>> score.setScoreStruct(ScoreStruct(timesig=(3, 4), tempo=72))
>>> n.scorestruct()
ScoreStruct(timesig=(3, 4), tempo=72)

scoringEvents(groupid='', config=None, parentOffset=None)[source]¶

Returns its notated form as scoring.Notations

These can then be converted into notation via some of the available backends: musicxml or lilypond

Parameters:

groupid – passed by an object higher in the hierarchy to mark this objects as belonging to a group
config (Optional[CoreConfig]) – a configuration to customize rendering
parentOffset (Optional[Fraction]) – if given this should be the absolute offset of this object’s parent

Return type:

list[Notation]

Returns:

A list of scoring.Notation which best represent this object as notation

scoringParts(config=None)[source]¶

Returns this object as a list of scoring UnquantizedParts.

Parameters:: config (Optional[CoreConfig]) – if given, this config instead of the active config will be used
Return type:: list[UnquantizedPart]
Returns:: a list of unquantized parts

This method is used internally to generate the parts which constitute a given MObj prior to rendering, but might be of use itself so it is exposed here.

An maelzel.scoring.UnquantizedPart is an intermediate format used by the scoring package to represent notated events. It represents a list of non-simultaneous Notations, unquantized and independent of any score structure

setPlay(**kws)[source]¶

Set any playback attributes, returns self

Parameters:: **kws – any argument passed to play() (delay, dur, chan, gain, fade, instr, pitchinterpol, fadeshape, params, priority, position).
Return type:: Self
Returns:: self. This allows to chain this to any constructor (see example)

Attribute	Type	Descr
instr	str	The instrument preset to use
delay	float	Delay in seconds, added to the start of the object
chan	int	The channel to output to, channels start at 1
fade	float	The fade time; can also be a tuple (fadein, fadeout)
fadeshape	str	One of ‘linear’, ‘cos’, ‘scurve’
pitchinterpol	str	One of ‘linear’, ‘cos’, ‘freqlinear’, ‘freqcos’
gain	float	A gain factor applied to the amplitud of this object. Dynamic argument (kgain)
position	float	Dynamic argument. Panning position (0=left, 1=right). Dynamic argument (kpos)
skip	float	Skip time of playback; allows to play a fragment of the object. NB: set the delay to the -skip to start playback at the original time but from the timepoint specified by the skip param
end	float	End time of playback; counterpart of `skip`, allow to trim playback of the object
sustain	float	An extra sustain time. This is useful for sample based instruments
transpose	float	Transpose the pitch of this object only for playback
glisstime	float	The duration (in beats) of the glissando for events with glissando. A short glisstime can be used for legato playback in non-percusive instruments
priority	int	The order of evaluation. Events scheduled with a higher priority are evaluated later in the chain
args	dict	Named arguments passed to the playback instrument
gliss	float/ bool	An object can be set to have a playback only gliss. It is equivalent to having a gliss., but the gliss is not displayed as notation.

Example:

# a piano note
>>> from maelzel.core import *
# Create a note with predetermined instr and panning position
>>> note = Note("C4+25", dur=0.5).setPlay(instr="piano", position=1)
# When .play is called, the note will play with the preset instr and position
>>> note.play()

See also

addSymbol(), playargs

setProperty(key, value)[source]¶

Set a property, returns self

Any MObj can have user-defined properties. These properties are optional: before any property is created the .properties attribute is None. This method creates the dict if it is still None and sets the property.

Parameters:

key (str) – the key to set
value – the value of the property

Return type:

Self

Returns:

self (similar to setPlay or setSymbol, to allow for chaining calls)

Example

>>> from maelzel.core import *
>>> n = Note("4C", 1)
>>> n.setProperty('foo', 'bar')
4C:1♩
>>> # To query a property do:
>>> n.getProperty('foo')
bar
>>> # Second Method: query the properties attribute directly.
>>> # WARNING: if no properties were set, this attribute would be None
>>> if n.properties:
...     foo = n.properties.get('foo')
...     print(foo)
bar

See also

getProperty(), properties

show(fmt=None, external=None, backend='', scorestruct=None, config=None, resolution=None)[source]¶

Show this as notation.

Parameters:

external (Optional[bool]) – True to force opening the image in an external image viewer, even when inside a jupyter notebook. If False, show will display the image inline if inside a notebook environment. To change the default, modify config[‘openImagesInExternalApp’]
backend – backend used when rendering to png/pdf. One of ‘lilypond’, ‘musicxml’. If not given, use default (see config[‘show.backend’])
fmt (Optional[str]) – one of ‘png’, ‘pdf’, ‘ly’. None to use default.
scorestruct (Optional[ScoreStruct]) – if given overrides the current/default score structure
config (Optional[CoreConfig]) – if given overrides the current/default config
resolution (Optional[int]) – dpi resolution when rendering to an image, overrides the config key ‘show.pngResolution’

Return type:

None

timeRangeSecs(parentOffset=None, scorestruct=None)[source]¶

The absolute time range, in seconds

Parameters:

parentOffset (Optional[Fraction]) – if given, use this offset as parent offset. This is useful if the parent’s offset has already been calculated
scorestruct (Optional[ScoreStruct]) – use this scorestruct to calculate absolute time. This is useful if the scorestruct is already known.

Return type:

tuple[Fraction, Fraction]

Returns:

a tuple (absolute start time in seconds, absolute end time in seconds)

timeScale(factor, offset=0)[source]¶

Create a copy with modified timing by applying a linear transformation

Parameters:

factor (Union[float, Rational, Fraction]) – a factor which multiplies all durations and start times
offset (Union[float, Rational, Fraction]) – an offset added to all start times

Return type:

Self

Returns:

the modified object

timeShift(timeoffset)[source]¶

Return a copy of this object with an added offset

Parameters:: timeoffset (Union[float, Rational, Fraction]) – a delta time added
Return type:: Self
Returns:: a copy of this object shifted in time by the given amount

timeShiftInPlace(timeoffset)[source]¶

Shift the time of this by the given offset (inplace)

Parameters:: timeoffset (Union[float, Rational, Fraction]) – the time delta (in quarterNotes)
Return type:: None

timeTransform(timemap, inplace=False)[source]¶

Apply a time-transform to this object

Parameters:

timemap (Callable[[Fraction], Fraction]) – a function mapping old time to new time
inplace – if True changes are applied inplace

Return type:

Self

Returns:

the resulting object (self if inplace)

Note

time is conceived as abstract ‘beat’ time, measured in quarter-notes. The actual time will be also determined by any tempo changes in the active score structure.

transpose(interval)[source]¶

Transpose this object by the given interval

Parameters:: interval (int | float) – the interval in semitones
Return type:: Self
Returns:: the transposed object

transposeByRatio(ratio)[source]¶

Transpose this by a given frequency ratio, if applicable

A ratio of 2 equals to transposing an octave higher.

Parameters:: ratio (float) – the ratio to transpose by
Return type:: _MObjT
Returns:: a copy of this object, transposed by the given ratio

Example

>>> from maelzel.core import *
>>> n = Note("4C")
# A transposition by a ratio of 2 results in a pitch an octave higher
>>> n.transposeByRatio(2)
5C

unquantizedScore(title='')[source]¶

Create a maelzel.scoring.UnquantizedScore from this object

Parameters:: title – the title of the resulting score (if given)
Return type:: UnquantizedScore
Returns:: the Arrangement representation of this object

An UnquantizedScore is a list of UnquantizedPart, which is itself a list of Notation. An Arrangement represents an unquantized score, meaning that the Notations within each part are not split into measures, nor organized in beats. To generate a quantized score see quantizedScore()

This method is mostly used internally when an object is asked to be represented as a score. In this case, an Arrangement is created first, which is then quantized, generating a QuantizedScore

See also

quantizedScore(), QuantizedScore

withExplicitOffset(forcecopy=False)[source]¶

Copy of self with explicit times

If self already has explicit offset and duration, self itself is returned. If you relie on the fact that this method returns a copy, use forcecopy=True

Parameters:: forcecopy – if forcecopy, a copy of self will be returned even if self already has explicit times
Returns:: a clone of self with explicit times

Example

>>> n = None("4C", dur=0.5)
>>> n
4C:0.5♩
>>> n.offset is None
True
# An unset offset resolves to 0
>>> n.withExplicitTimes()
4C:0.5♩:offset=0
# An unset duration resolves to 1 quarternote beat
>>> Note("4C", offset=2.5).withExplicitTimes()
4C:1♩:offset=2.5

write(outfile, backend='', resolution=None)[source]¶

Export to multiple formats

Formats supported: pdf, png, musicxml (extension: .xml or .musicxml), lilypond (.ly), midi (.mid or .midi) and pickle

Parameters:

outfile (str) – the path of the output file. The extension determines the format. Formats available are pdf, png, lilypond, musicxml, midi, csd and pickle.
backend – the backend used when writing as pdf or png. If not given, the default defined in the active config is used (key: ‘show.backend’). Possible backends: lilypond; musicxml (uses MuseScore to render musicxml as image so MuseScore needs to be installed)
resolution (Optional[int]) – image DPI (only valid if rendering to an image) - overrides the config key ‘show.pngResolution’

Return type:

None

Formats¶

pdf, png: will render the object as notation and save that to the given format
lilypond: .ly extension. Will render the object as notation and save it as lilypond text
midi: .mid or .midi extension. At the moment this is done via lilypond, so the midi
produced follows the quantization process used for rendering to notation. Notice that midi cannot reproduce many features of a maelzel object, like microtones, and many complex rhythms will not be translated correctly
pickle: the object is serialized using the pickle module. This allows to load it
via pickle.load: myobj = pickle.load(open('myobj.pickle'))