Scales & Chords

Scales and chords are collections of intervals that define harmonic context.

Defining Scales

A scale is an ordered collection of intervals from the root:

; Major scale
scale Major = { R, M2, M3, P4, P5, M6, M7 }

; Natural minor scale
scale Minor = { R, M2, m3, P4, P5, m6, m7 }

; Pentatonic scale
scale Pentatonic = { R, M2, M3, P5, M6 }

; Blues scale
scale Blues = { R, m3, P4, A4, P5, m7 }

Using Scale Degrees

Once you have a scale, use <n> to reference its degrees:

scale Major = { R, M2, M3, P4, P5, M6, M7 }

; Create a melody using scale degrees
let melody = | <1> <3> <5> <3> <1> |

melody

Scale degrees wrap around with octaves:

scale Major = { R, M2, M3, P4, P5, M6, M7 }

let octave = | <1> <8> |     ; R, R+ (octave)
let ninth = | <1> <9> |      ; R, M2+ (9th = 2nd + octave)

Defining Chords

Chords use square brackets and represent simultaneous notes:

; Major triad
chord MajorTriad = [ R, M3, P5 ]

; Minor triad
chord MinorTriad = [ R, m3, P5 ]

; Dominant 7th
chord Dom7 = [ R, M3, P5, m7 ]

; Major 7th
chord Maj7 = [ R, M3, P5, M7 ]

Chord Progressions

Build progressions using scale degrees:

scale Major = { R, M2, M3, P4, P5, M6, M7 }

; I-IV-V-I progression
let progression = | <1> <4> <5> <1> |

progression

Modes

Create modes by starting from different scale degrees:

scale Major = { R, M2, M3, P4, P5, M6, M7 }

; Dorian mode (start from 2nd degree)
let Dorian = Major |> rotate 1

; Mixolydian mode (start from 5th degree)
let Mixolydian = Major |> rotate 4

How Scales Are Applied

When you define a scale with scale, it becomes the active scale context for interpreting scale degrees (<1>, <2>, etc.).

Same Melody, Different Scales

The same scale degree pattern produces different sounds depending on the active scale:

; Major scale - bright, happy
scale Major = { R, M2, M3, P4, P5, M6, M7 }
let major_melody = | <1> <2> <3> <4> <5> |

major_melody  ; Output: R, M2, M3, P4, P5

; Minor scale - darker, melancholic
scale Minor = { R, M2, m3, P4, P5, m6, m7 }
let minor_melody = | <1> <2> <3> <4> <5> |

minor_melody  ; Output: R, M2, m3, P4, P5

Reusing Patterns Across Scales

Define a pattern once, apply it to different scales:

scale Major = { R, M2, M3, P4, P5, M6, M7 }

; A simple arpeggio pattern using scale degrees
let arpeggio = | <1> <3> <5> <8> |

; In Major: R, M3, P5, R+ (happy major chord)
arpeggio

scale Minor = { R, M2, m3, P4, P5, m6, m7 }

; Same pattern, minor context
let arpeggio = | <1> <3> <5> <8> |

; In Minor: R, m3, P5, R+ (sad minor chord)
arpeggio

Modal Interchange

Switch scales mid-piece for modal color:

scale Major = { R, M2, M3, P4, P5, M6, M7 }
let verse = | <1> <5> <3> <1> |

scale Minor = { R, M2, m3, P4, P5, m6, m7 }
let chorus = | <1> <5> <3> <1> |

; verse uses Major intervals, chorus uses Minor
verse ++ chorus

Transposition

Transpose scales and chords easily:

scale Major = { R, M2, M3, P4, P5, M6, M7 }

let melody = | <1> <3> <5> |

; Transpose by interval
let transposed = melody |> transpose P5

transposed

Common Scales Reference

Name	Intervals
Major	R, M2, M3, P4, P5, M6, M7
Natural Minor	R, M2, m3, P4, P5, m6, m7
Harmonic Minor	R, M2, m3, P4, P5, m6, M7
Melodic Minor	R, M2, m3, P4, P5, M6, M7
Pentatonic Major	R, M2, M3, P5, M6
Pentatonic Minor	R, m3, P4, P5, m7
Blues	R, m3, P4, A4, P5, m7
Whole Tone	R, M2, M3, A4, A5, A6