music.rhythm_to_durations¶

music.rhythm_to_durations(durations=(4, 2, 2, 4, 1, 1, 1, 1, 2, 2, 4), freqs=None, duration=0.25, bpm=None, total_duration=None)[source]¶

Returns durations from rhythmic patterns.

Parameters:

durationsinterable of scalars: The relative durations of each item (e.g. note).
freqsiterable of scalars: The number of the entry’s duration that fits into the pulse. If supplied, durations is ignored.
durationscalar: A basic duration (e.g. for the pulse) in seconds.
bpmscalar: The number of beats per second. If supplied, duration is ignored.
total_duration: scalar: The total duration of the sequence in seconds. If supplied, both BPM and duration are ignored.

Returns:

dursList of durations in seconds.

Notes

The durations parameter is considered to be in a temporal notation for durations/rhythm: each entry is a relative duration to be multiplied by the base duration given through duration, BPM or total_duration:

durs = [i*duration for i in durations]

The frequencies parameter is considered to be in a frequential notation: each entry is the number of the entry that fits a same duration (also given through duration, BPM or total_duration):

durs = [duration/i for i in freqs]

The examples above yield (two by two) the same sequences of durations by using duration=0.25 when in temporal notation or duration=4 when in frequency notation.

To facilitate the description of rhythms (e.g. for tuplets), some set of durations might be an iterable inside durations or frequencies. In this case:

### if mode is temporal:
    total_dur = cell[0]*duration
    # durations are proportional to remaining values:
    d_ = [i/sum(cell[1:]) for i in cell[1:]]
    durs = [i*total_dur for i in d_]
### if mode is frequential:
    total_dur = duration/cell[0]
    # durations are inversely proportional to remaining values:
    d_ = [i/sum(cell[1:]) for i in cell[1:]]
    durs = [i*total_dur for i in d_]

An example for achieving the same sequence of durations through temporal or frequential notation and with cells for tuplets is the last two sequences of the examples.

It might be a good idea to incorporate also this notation:

d2 = [1, 4, 1, 4]  # [quarter note + 4 sixteenth notes] x 2

Cite the following article whenever you use this function.

References

[1]

Fabbri, Renato, et al. “Musical elements in the discrete-time representation of sound.” arXiv preprint arXiv:abs/1412.6853 (2017)

Examples

>>> dt = [4, 2, 2, 4, 1,1,1,1, 2, 2, 4]
>>> durs0 = rhythm_to_durations(dt, duration=.25)
>>> df = [4, 8, 8, 4, 16, 16, 16, 16, 8, 8, 4]
>>> durs0_ = rhythm_to_durations(freqs=df, duration=4)
>>> dtut = [4,2,2, [8, 1,1,1], 4, [4, 1,1,.5,.5], 3,1, 3,1, 4]
>>> durs1 = rhythm_to_durations(dtut)
>>> dtuf2 = [4,8,8, [2, 3,3,3], 4, [4, 3,3,6,6], 16/3, 16, 16/3, 16, 4]
>>> durs1_ = rhythm_to_durations(freqs=dtut2, duration=4)