Music::Scales 0.07

Music::Scales can supply necessary notes / offsets for musical scales.

SYNOPSIS

use Music::Scales;

my @maj = get_scale_notes(Eb); # defaults to major
print join(" ",@maj); # "Eb F G Ab Bb C D"
my @blues = get_scale_nums(bl); # bl,blu,blue,blues
print join(" ",@blues); # "0 3 5 6 7 10"
my %min = get_scale_offsets (G,mm,1); # descending melodic minor
print map {"$_=$min{$_} "} sort keys %min; # "A=0 B=-1 C=0 D=0 E=-1 F=0 G=0"

Given a keynote A-G(#/b) and a scale-name, will return the scale, either as an array of notenames or as a hash of semitone-offsets for each note.

METHODS

get_scale_nums($scale[,$descending])

returns an array of semitone offsets for the requested scale, ascending/descending the given scale for one octave. The descending flag determines the direction of the scale, and also affects those scales (such as melodic minor) where the notes vary depending upon the direction. Scaletypes and valid values for $scale are listed below.

get_scale_notes($notename[,$scale,$descending,$keypref])

returns an array of notenames, starting from the given keynote. Enharmonic equivalencies (whether to use F# or Gb, for instance) are calculated based on the keynote and the scale. Basically, it attempts to do the Right Thing if the scale is an 8-note one, (the 7th in G harmonic minor being F# rather than Gb, although G minor is a flat key), but for any other scales, (Chromatic, blues etc.) it picks equivalencies based upon the keynote. This can be overidden with $keypref, setting to be either # or b for sharps and flats respectively. Cruftiness abounds here.

get_scale_offsets($notename[,$scale,$descending,$keypref])

as get_scale_notes(), except it returns a hash of notenames with the values being a semitone offset (-1, 0 or 1) as shown in the synopsis.

get_scale_MIDI($notename,$octave[,$scale,$descending])

as get_scale_notes(), but returns an array of MIDI note-numbers, given an octave number (-1..9).

get_scale_PDL($notename,$octave[,$scale,$descending])

as get_scale_MIDI(), but returns an array of PDL-format notes.

is_scale($scalename)

returns true if $scalename is a valid scale name used in this module.