Torbimusic Core

Mision

Provide a set of classes to solve many common needs for music theory programming.

Quick Start

Install

npm install -s @torbimusic/core

Use

import { Chord, Interval, Note, MajorScale, MinorScale } from '@torbimusic/core'

let note = Note.parse('C')
let chord = Chord.parse('Eb')
let interval = Interval.parse('2M')

let intervalFromCtoEb = note.intervalOf(chord.base.note) // 3m

intervalFromCtoEb.traspose(note) // Eb
interval.traspose(note) // F

chord.traspose(interval.add(intervalFromCtoEb))

let scaleC = MajorScale.from(note) // C Major

scaleC.triads // [C, Dm, Em, F, G, A, B°]

scaleC.traspose(interval) // D Major

Core Objects in the Library

As a summary, the most important objects to use are:

• Interval.
• Note.
• Chord.
• Scale.

Intervals

Represents the distance between two notes.

You can read this table as a summary of what an Interval is.

| Interval | Aliases | Quality | Grades | Semitones | Notes | |--|--|--|--|--|--| | 1 | T | PERFECT | 1 | 0 | 0 | | 2m | | MINOR | 2 | 1 | 1 | | 2 | 2M | MAJOR | 2 | 2 | 1 | | 2aug | | AUGMENTED | 2 | 3 | 1 | | 3m | 3m | MINOR | 3 | 3 | 2 | | 3 | 3M | MAJOR | 3 | 4 | 2 | | 4J | 4 | PERFECT | 4 | 5 | 3 | | 4aug | 4+ 4# | AUGMENTED | 4 | 6 | 3 | | 5J | 5 | PERFECT | 5 | 7 | 4 | | 5aug | 5+ 5# | AUGMENTED | 5 | 8 | 4 | | 6m | | MINOR | 6 | 8 | 5 | | 6M | 6 | MAJOR | 6 | 9 | 5 | | 6aug | 6+ 6# | AUGMENTED | 6 | 10 | 5 | | 7dim | 7° | DIMINISHED | 7 | 9 | 6 | | 7m | | MINOR | 7 | 10 | 6 | | 7M | 7 | MAJOR | 7 | 11 | 6 | | 8 | | PERFECT | 8 | 12 | 7 | | 9m | | MINOR | 9 | 13 | 8 | | 9 | 9M | MAJOR | 9 | 14 | 8 | | 11 | 11J | PERFECT | 11 | 17 | 10 | | 11aug | 11+ 11# | AUGMENTED | 11 | 18 | 10 | | 13m | | MINOR | 13 | 20 | 12 | | 13 | 13M | MAJOR | 13 | 21 | 12 |

How to create an Interval

Use of for create an Interval from the distance between two notes.

let a = Note.parse('A')
let c = Note.parse('C')

Interval.of(a, c) // 3M

The intervals can be represented as a difference of grades and semitones.

To obtain an Interval from this two things, you must use fromGradesAndSemitones method.

let grades = 3
let semitones = 4
Interval.fromGradesAndSemitones(grades, semitones) // 3M

Another way to obtain an Interval is using parse and providing a string representation of the Interval, using the table writed above.

Interval.parse('3M') // 3M

Another utility methods for Intervals

Use the traspose just for traspose a note as the Interval value.

let note = Note.parse('C')
let interval = Interval.parse('3M')

interval.traspose(note) // 'E'

Use the add method to compose two Intervals.

let _2M = Interval.parse('2M')
let _2m = Interval.parse('2m')

_2M.add(_2m) // 3m

Note

Represent a musical Note.

How to create an Note

Use fromNote for create a Note from an American or SouthernEuropean note and a NoteAlteration.

Note.fromNote(AmericanNote.C, NoteAlteration.SHARP) // C#
Note.fromNote(SouthernEuropean.DO, NoteAlteration.SHARP) // C#

Use parse to create a Note from a string. Can be an American or SouthernEuropean notation.

Note.parse('C') // C
Note.parse('DO') // C

Utility methods in Note

Use enharmonicToNoteAbove and enharmonicToNoteBelow to get the enharmonics of a note:

Note.parse('C#').enharmonicToNoteAbove() // Db

Note.parse('Eb').enharmonicToNoteBelow() // D#

Use intervalOf to get the interval between the current note and the provided one:

let c = Note.parse('C')
let eb = Note.parse('Eb')

c.intervalOf(eb) // 3m