elm-maestro

This library provides music theory abstractions and functionalities.

Alpha stage: this library is not considered stable yet, and could be subject to API changes in the future.

Installation

elm-package oleiade/elm-maestro

or add the dependency in your elm-package.json file directly

"oleiade/elm-maestro": "0.1.0 <= v < 0.2.0"

Usage

Types and abstractions

Pitch

The Maestro.PitchClass module exposes the following types:

type alias Pitch =
    { class : PitchClass, accidental : Accidental }

type PitchClass
    = C
    | D
    | E
    | F
    | G
    | A
    | B

type Accidental
    = Natural
    | Sharp
    | Flat
    | SharpSharp
    | FlatFlat

in order to represent pitches/pitches as follows:

import Maestro.PitchClass exposing(PitchClass(..), Accidental(..))

cNatural = newPitch C Natural
dSharp = newPitch D Sharp
bFlat = newPitch B Flat

Note

The Maestro.Note module exposes the following types:

type alias Note =
    { pitch : Pitch
    , octave : Octave
    }

type alias Octave =
    Int

in order to represent notes as follows:

import Maestro.PitchClass exposing (Pitch, PitchClass(..), Accidental(..))
import Maestro.Note exposing (newNote)

e3Natural = newNote E Natural 3
f4Sharp = newNote F Sharp 4
a1Flat = newNote A Flat 1

Interval

The Maestro.Interval module exposes the following type:

type Interval
    = Unison
    | MinorSecond
    | MajorSecond
    | MinorThird
    | MajorThird
    | PerfectFourth
    | PerfectFifth
    | MinorSixth
    | MajorSixth
    | MinorSeventh
    | MajorSeventh
    | PerfectOctave
    | MinorNinth
    | MajorNinth
    | MinorTenth
    | MajorTenth
    | PerfectEleventh
    | AugmentedEleventh
    | PerfectTwelfth
    | MinorThirteen
    | MajorThirteen
    | MinorFourteenth
    | MajorFourteenth
    | DoubleOctave

and will allow you to find the note at interval from a start note like follows:

import Maestro.PitchClass exposing (PitchClass(..), Accidental(..), newPitch)
import Maestro.Interval exposing (Interval(..), addInterval)

example : Note
example =
  addInterval (newNote C Natural 3)  MajorThird

Scale

A Scale is represented as a list of Pitch. It is built from a pitch and a mode as follows:

import Maestro.PitchClass exposing (newPitch, PitchClass(..), Accidental(..))
import Maestro.Scale exposing (scale, Mode(..))

example : Scale
example =
    doSomethingWith <| scale (newPitch C Natural) Major