Dodecaphony

Dodecaphony calculates twelve tone rows for you. To learn more about what this means, read this.

Dodecaphony is a ruby gem. Install with

gem install dodecaphony

Examples

First, you'll need a Dodecaphony::Row object. Dodecaphony::Row requires an array of 12 strings, each representing a unique pitch. Each pitch must begin with a valid letter name (a through g) and can be followed by one or more accidentals. #, +, b and - are the four valid accidentals.

my_row = Dodecaphony::Row.new %w[a a# b c c# d d# e f f# g g#]

A row can be converted to either an array of pitch names, or a string with pitch names separated by a space.

my_row.to_a    # ['a', 'a#', 'b', 'c', 'c#', 'd', 'd#', 'e', 'f', 'f#', 'g', 'g#']

my_row.to_s    # "a a# b c c# d d# e f f# g g#"

You can also ask a row to respell itself, favoring flats or sharps:

tone_row = Dodecaphony::Row.new %w[ a f# g ab e f b bb d c# c eb ]

tone_row.spell_with_sharps # ["A", "F#", "G", "G#", "E", "F", "B", "A#", "D", "C#", "C", "D#"]

tone_row.spell_with_flats # ["A", "Gb", "G", "Ab", "E", "F", "B", "Bb", "D", "Db", "C", "Eb"]

The Dodecaphony::Calculator class initializes with a Dodecaphony::Row object.

tone_row = Dodecaphony::Row.new %w[ a f# g ab e f b bb d c# c eb ]
calc = Dodecaphony::Calculator.new tone_row

The calculator can then return any prime, inversion, retrograde, or retrograde inversion. Each of these rows is a method of the calculator object, the names being the initial of the type of row you want, followed by the number of the row you want. Observe:

#  "p" followed by 0 through 11 returns the corresponding prime row
calc.p0    # ["a", "f#", "g", "ab", "e", "f", "b", "bb", "d", "c#", "c", "eb"]

#  "r" followed by 0 through 11 returns the corresponding retrograde
calc.r11   # ["d", "b", "c", "c#", "a", "bb", "e", "eb", "g", "f#", "f", "ab"]

#  "i" followed by 0 through 11 returns the corresponding inversion
calc.i2    # ["b", "d", "c#", "c", "e", "eb", "a", "bb", "f#", "g", "ab", "f"]

# "ri" followed by 0 through 11 returns the corresponding retrograde inversion
calc.ri6   # ["a", "c", "b", "bb", "d", "c#", "g", "ab", "e", "f", "f#", "eb"]