music.lua

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#Music

A library to aid the use of musical concepts in lua projects.

This library expects that you have some basis and understand of music theory. It is after all a library implementing music theory! If you need help, feel free to contact me.

##Installation This music.lua can be dropped into a project, and required as thus: music = require "music"

##Examples

###Transposing a frequency up a fifth.

    local freq = 634
    print(freq * music.pitchRatio(music.interval("P5")))
    -- 949.92668673982

###Testing if two notes are enharmonic

    local CSharp = "C#"
    local BSharps = "B##"
    local FNatural = "F"

    print(music.noteToInt(CSharp) == music.noteToInt(BSharps))
    print(music.noteToInt(CSharp) == music.noteToInt(FNatural))
    print(music.noteToInt(BSharps) == music.noteToInt(FNatural))
    -- true
    -- false
    -- false

###Printing out the pitches for a G# harmonic minor scale:

    local GSMinor = music.scale("G#",music.scales.harmonic)
    local outtable = {}
    for _,n in ipairs(GSMinor) do
        table.insert(outtable,music.intToNote(n))
    end
    print(table.concat(outtable,","))
    -- G#,A#,B,C#,D#,E,F#

##Function Reference

###music.pitchRatio(semitones,temperament) Returns a ratio that will modify a sound by semitones in equal temperament. If a different temperament is given then it is used instead. Available temperaments can be found in the table music.temperaments.

###music.midiToFrequency(midinote [, temperament [, bfreq [, bnote]]]) Returns the frequency value of a midi note using temperament (defaults to equal). If bfreq (base frequency) is given it will use that as the frequency to base calculations on. If you want to use a different note to tune your unequal temperament, use bnote (midi note) to specify which frequency you are using.

    local D = math.floor(music.midiToFrequency(62))
    print(music.midiToFrequency(69,"pythagorean"))
    print(music.midiToFrequency(69,"pythagorean",D,62))
    print(music.midiToFrequency(69,"equal"))
    print(music.midiToFrequency(69,"equal",D,62))

###music.noteToInt(notename) Given a valid note (as a string), returns an integer value describing the notes pitch in relation to a C. Returns an integer between 0 and 11.

A valid note pitch is one where the first character is the base note, and every character after it is either a # or b, that will raise or lower the pitch. For instance, C is the same as Dbb or even Ebbbb.

###music.intToNote(noteint) Does the reverse of music.noteAsInt. Returns a notestring.

###music.normalizeNoteName(notename) Given a note string, returns a sane version of the notestring.

    local crazynote = "Cbb#b#bbb##"
    print(music.normalizeNoteName(crazynote))
    -- A#

###music.interval(interval) Gives the number of semi tones needed to acquire the specified interval. A valid interval will always have a quality, and then a number specifying the interval. Valid qualities are P for perfect, M for major, m for minor, d for diminished, and `A for augmented.

###music.chord(root,chord) Gets a chord chord built off of root. Chord is a table with intervals inside. Example: d_minor_chord = music.chord("D",music.chords.minor) -- Result: {2, 5, 9}

###music.diatonicChord(root,scale [, ctype [, inversion]]) Gets a diatonic chord built off of root in the specified scale (key) Note that root is the position in the scale, so the fifth scale degree would be a 5. If ctype can be used to change what kind of chord you get. Available options are "triad" and "7", for a triad and seventh chords. inversion is the inversion number of the chord, 0 is root position, 1 is the first inversion, 2 the second and so on.

local scale = music.scale("D",music.scales.major)
music.diatonicChord(5,scale,"7",3) -- Gets a V4-2 chord.

###music.scale(key,scale) Given a key and scale, returns a table of the pitches in a scale. Example: local DMaj = music.scale("D",music.scales.major)

##Variable Reference

###Scales ####Major music.scales.major

####Minor music.scales.minor
music.scales.harmonicminor
music.scales.melodicminor

####Modes music.scales.dorian
music.scales.phrygian
music.scales.lydian
music.scales.mixolydian
music.scales.aeolian
music.scales.locrian

####Other music.scales.wholetone

###Chords music.chords.major
music.chords.minor
music.chords.dim
music.chords.MM7
music.chords.Mm7
music.chords.mm7
music.chords.dim7
music.chords.hdim7

###Misc music.temperaments - List of the available temperament.

##TODO

• Fix intervals so you can have a dim 7. Perhaps just use a simple table look up? No fancy trickery?