mystic.cr

Mystic is a music theory library for Crystal. It provides classes and methods for many music applications.

Features:

• Notes
• Intervals
• Scales
• Chords
• Set theory (pitch classes and pitch class sets)

Installation

1. Add the dependency to your shard.yml:

   dependencies:
     mystic:
       github: seanyeh/mystic.cr

2. Run shards install

Usage

Here is some sample code showing what you can do with mystic. Check out the docs for a complete API reference.

require "mystic"

# Notes
g5 = Mystic::Note.new("g5")
c4 = Mystic::Note.new("C") # default octave is 4

# Intervals
p12 = g5 - c4 # Interval of a Perfect 12th
p5 = p12.simple # Interval of a Perfect 5th
p4 = p5.invert # Interval of a Perfect 4th

i = Mystic::Interval.new("m-2") # Descending minor 2nd
a4 = p5 + i # Interval of an Augmented 4th

# Scales
g_lydian = Mystic::Scale.new(g5, "lydian")
g_lydian.note_names
# => ["G", "A", "B", "C#", "D", "E", "F#"]

a_lydian = scale + Mystic::Interval.new("M2") # Transpose up a M2

# Chords
eb4 = Mystic::Note.new("Eb")
g4 = Mystic::Note.new("G")
cm = Mystic::Chord.new([c4, eb4, g4])

cm.quality # => "minor"
cm == Mystic::Chord.new(c4, "minor") # => true
cm.get(3) # Gets the 3rd of the chord (Note object Eb4)

cm.invert.notes
# => Note objects Eb4, G4, C5

Mystic::Chord.new("Cmb9#11").note_names
# => ["C", "Eb", "G", "Bb", "Db", "F#"]

Mystic::Chord.new(c4, "mystic").note_names
# => ["C", "F#", "Bb", "E", "A", "D"]

# Set Theory
pc_set = Mystic::Chord.new("F#").pitch_class_set # PitchClassSet of [6, 10, 1]
pc_set.prime_form
# => PitchClassSet of [0, 3, 7]

pc_set.interval_vector
# => [0, 0, 1, 1, 1, 0]

pc_set.forte_number
# => "3-11B"

Contributing

1. Fork it (https://github.com/seanyeh/mystic.cr/fork)
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

Contributors

• Sean Yeh - creator and maintainer