API Reference¶

tonal_py exposes 23 namespaces, each mirroring a @tonaljs/* package. All function names use Python snake_case (the JS docs use camelCase — see Naming Conventions for the mapping).

Foundation layer¶

The lowest-level music-theory primitives. Most users never touch these directly.

Namespace	What it does
Core	Re-exports of the foundation layer + a `deprecate` helper
Pcset	Pitch class set utilities (chroma, modes, subset/superset)

Notes and intervals¶

Namespace	What it does
Note	Parse, transpose, simplify, enharmonic-spell notes
Interval	Parse and arithmetic on intervals
Midi	MIDI ↔ note name ↔ frequency conversions

Chords and scales¶

Namespace	What it does
Chord	Parse chord names ("Cmaj7", "F#dim/A"), get notes, detect from notes
ChordType	The 106-entry chord-type dictionary
Scale	Build scales from a tonic + type, detect, find modes
ScaleType	The 92-entry scale-type dictionary
Key	Major/minor key with diatonic chords + harmonic functions
Mode	The 7 diatonic modes with triads and seventh chords
RomanNumeral	Roman numeral analysis (I, IV, V7, bVII...)

Voicings and rhythm¶

Namespace	What it does
Voicing	Concrete pitch realizations of chords in a range
VoicingDictionary	Pre-built voicing libraries
VoiceLeading	Voice-leading strategies for chord sequences
RhythmPattern	Rhythm pattern generators (binary, hex, euclidean)
TimeSignature	Time signature parsing (simple/compound/additive)
DurationValue	Note duration values (whole, quarter, dotted)

Notation and utilities¶

Namespace	What it does
AbcNotation	ABC notation ↔ scientific notation
Range	MIDI / chromatic ranges between waypoint notes
Progression	Convert chord progressions ↔ roman numerals
Collection	Generic array helpers (range, rotate, shuffle, permutations)