rb-music
rb-music is a Ruby gem for working with musical notes, scales and intervals. It is basically a direct port of the wonderful music.js library by Greg Jopa.
Installation
In your Gemfile:
gem 'rb-music', git: 'https://github.com/mwise/rb-music', branch: 'master'
In your Ruby code:
require 'rb-music'
Overview
Note
Note.from_latin(name): Note by latin name and octave
n = Note.from_latin('A4'); # single note
n.frequency # 440
n.latin # "A"
n.octave # 4
n.midi_note_number # 69
n = Note.from_latin('C4') # base note for scale
n.scale('major') # NoteSet built from the given note and scaleInterval
Interval.from_name(name): Interval by name
Interval.from_semitones(num): Interval by semitones
Interval.from_name('fifth') # define by name
whole_step = Interval.from_semitones(2) # define by # of semitones
c = Note.from_latin('C3')
# use intervals to transpose notes
d = c.add(whole_step)
# use intervals to define chords
cmaj = c.add(['unison','major third','fifth'])