kennethreitz 69ddb1eb64 Rewrite chord analysis with musically accurate models
intervals: now returns semitone counts (integers) instead of Hz
  differences — octave-invariant and musically meaningful

harmony: frequency ratio simplicity model — reduces each pairwise
  frequency ratio to simplest form and scores by 1/(num+denom).
  Simple ratios (octave 2:1, fifth 3:2) score highest.

dissonance: Plomp-Levelt roughness with Bark-scale critical bandwidth
  (Zwicker & Terhardt 1980). Models sensory roughness from interfering
  fundamentals — peaks when freq difference ≈ critical bandwidth.

beat_frequencies: new property returning all pairwise beat frequencies
  as sorted (tone, tone, hz) tuples

beat_pulse: returns smallest non-zero beat frequency (most perceptible)

All properties have detailed docstrings with psychoacoustic references,
perceptual ranges, and usage examples.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-03-22 06:13:05 -04:00
2018-09-02 04:13:48 -04:00

PyTheory: Music Theory for Humans

This (work in progress) library attempts to make exploring music theory approachable to humans.

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True Scale -> Pitch Evaluation

>>> from pytheory import TonedScale

>>> c_minor = TonedScale(tonic='C4')['minor']

>>> c_minor
<Scale I=C4 II=D4 III=Eb4 IV=F4 V=G4 VI=Ab4 VII=Bb5 VIII=C5>

>>> c_minor[0].pitch()
523.251130601197

>>> c_minor["I"].pitch(symbolic=True)
440*2**(1/4)

>>> c_minor["tonic"].pitch(temperament='pythagorean', symbolic=True)
14080/27

Audibly play a note (or chord)

>>> from pytheory import play
play(c_minor[0], t=1_000)

Chord Fingerings for Custom Tunings

>>> from pytheory import Tone, Fretboard, CHARTS

>>> tones = (
...     Tone.from_string("F2"),
...     Tone.from_string("C3"),
...     Tone.from_string("G3"),
...     Tone.from_string("D4"),
...     Tone.from_string("A5"),
...     Tone.from_string("E5")
... )

>>> fretboard = Fretboard(tones=tones)
>>>
>>> c_chord = CHARTS['western']["C"]

>>> print(c_chord.fingering(fretboard=fretboard))
(0, 0, 0, 3, 3, 3)

It can also generate charts for all known chords for any instrument (accuracy to be determined!).

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