librosa.key_to_degrees

librosa.key_to_degrees(key)[source]

Construct the diatonic scale degrees for a given key.

Parameters:

keystr

Must be in the form TONIC:key. Tonic must be upper case (CDEFGAB), key must be lower-case (maj, min, ionian, dorian, phrygian, lydian, mixolydian, aeolian, locrian).

The following abbreviations are supported for the modes: either the first three letters of the mode name (e.g. “mix”) or the mode name without “ian” (e.g. “mixolyd”).

Both major and maj are supported as abbreviations.

Single and multiple accidentals (b!♭ for flat, or #♯ for sharp) are supported.

Examples: C:maj, C:major, Dbb:min, A♭:min, D:aeo, E𝄪:phryg.

Returns:

degreesnp.ndarray: An array containing the semitone numbers (0=C, 1=C#, … 11=B) for each of the seven scale degrees in the given key, starting from the tonic.

See also

key_to_notes

Examples

>>> librosa.key_to_degrees('C:maj')
array([ 0,  2,  4,  5,  7,  9, 11])

>>> librosa.key_to_degrees('C#:maj')
array([ 1,  3,  5,  6,  8, 10,  0])

>>> librosa.key_to_degrees('A:min')
array([ 9, 11,  0,  2,  4,  5,  7])

>>> librosa.key_to_degrees('A:min')
array([ 9, 11,  0,  2,  4,  5,  7])