Leiter is a TypeScript-based library designed to generate musical scales based on a given tonic, octave, and scale type. It simplifies the process of obtaining notes in the correct pitch for various scales, facilitating musical application development.
- Generate Scales: Easily retrieve scales based on the tonic, octave, and desired scale type.
- TypeScript Support: Built with TypeScript for type-safety and developer experience.
- Expandable: Developers can extend and add more scales as needed.
- Streamlined and Lightweight: Lean design without excess, clocking in at just 13.3kB unpacked size.
Using npm:
npm install leiterHere's a simple example:
import { generateScale } from 'leiter';
const scale = generateScale('A', 4, 'major');
console.log(scale); // ['A4', 'B4', 'C#5', 'D5', 'E5', 'F#5', 'G#5', 'A5']generateScale(tonic: string, octave: number, scaleName: ScaleName): string[]
tonic (NoteType): The root or starting note of the scale. It should be one of the standard note names (e.g., "C", "D#"). Please note that flat notes are note supported in the current release. Instead use the aquavalent sharp note.octave (Octave): The octave in which the scale is to be generated. Represented as numbers between 0 - 8, where "C4" is the Middle C.scaleName (ScaleType): The name of the scale pattern you want to generate. The library supports a vast array of scales, from standard major and minor scales to unique scales from diverse global traditions.
An array of string values, each representing a note with it's pitch in the generated scale.
type ScaleType = "major" | "minor" | "harmonicMinor" | "melodicMinor" | "pentatonicMajor" | "pentatonicMinor" | "bluesMinor" | "bluesMajor" | "phrygian" | "locrian" | "dorian" | "mixolydian" | "lydian" | "wholeTone" | "diminishedWholeHalf" | "diminishedHalfWhole" | "augmented" | "doubleHarmonic" | "hungarianGypsy" | "hungarianMinor" | "neapolitanMinor" | "neapolitanMajor" | "persian" | "romanianMinor" | "hirajoshi" | "inSen" | "iwato" | "kumoi" | "slendro" | "pelog" | "chineseMajor" | "chineseMinor" | "ragaBhairavi" | "ragaKafi" | "balinese";export type NoteType = "C" | "C#" | "D" | "D#" | "E" | "F" | "F#" | "G" | "G#" | "A" | "A#" | "B";export type Octave = 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8;| Scale Name | Formula | Description |
|---|---|---|
| Major | 2, 2, 1, 2, 2, 2, 1 | Bright, happy sound; commonly used in Western music |
| Minor | 2, 1, 2, 2, 1, 2, 2 | Sad, more emotional tone compared to major |
| Harmonic Minor | 2, 1, 2, 2, 1, 3, 1 | Combines elements of minor and middle-eastern music; characterized by a raised seventh note |
| Melodic Minor | 2, 1, 2, 2, 2, 2, 1 | Traditionally, raises the sixth and seventh notes when ascending and follows the natural minor when descending. |
| Pentatonic Major | 2, 2, 3, 2, 3 | Five-note scale; foundational to blues music |
| Pentatonic Minor | 3, 2, 2, 3, 2 | Five-note scale; foundational to blues music |
| Blues Minor | 3, 2, 1, 1, 3, 2 | Used in blues music; conveys feelings of melancholy |
| Blues Major | 2, 1, 1, 3, 2, 3 | Brighter blues sound |
| Phrygian | 1, 2, 2, 2, 1, 2, 2 | Dark, Spanish flavor; starts on the third degree of the major scale |
| Locrian | 1, 2, 2, 1, 2, 2, 2 | Unsettled, dissonant; starts on the seventh degree of the major scale |
| Dorian | 2, 1, 2, 2, 2, 1, 2 | Jazzy, starts on the second degree of the major scale |
| Mixolydian | 2, 2, 1, 2, 2, 1, 2 | Bright, but less so than major; starts on the fifth degree of the major scale |
| Lydian | 2, 2, 2, 1, 2, 2, 1 | Dreamy, starts on the fourth degree of the major scale |
| Whole Tone | 2, 2, 2, 2, 2, 2 | Dreamlike, lacking tonal center; all whole steps |
| Diminished Whole Half | 2, 1, 2, 1, 2, 1, 2, 1 | Symmetrical; creates tension and suspense |
| Diminished Half Whole | 1, 2, 1, 2, 1, 2, 1, 2 | Alternate form of diminished scale; intense dissonance |
| Augmented | 3, 1, 3, 1, 3 | Bright, raised pattern; every other note is augmented |
| Double Harmonic | 1, 3, 1, 2, 1, 3, 1 | Exotic, Middle Eastern and Gypsy flavor |
| Hungarian Gypsy | 2, 1, 3, 1, 1, 2, 1 | Similar to harmonic minor with augmented fourth |
| Hungarian Minor | 2, 1, 3, 1, 1, 3, 1 | Variant of harmonic minor with augmented fourth |
| Neapolitan Minor | 1, 2, 2, 2, 1, 3, 1 | Mix of Phrygian and harmonic minor |
| Neapolitan Major | 1, 2, 2, 2, 2, 2, 1 | Brighter variant of Neapolitan Minor |
| Persian | 1, 3, 1, 1, 2, 3, 1 | Middle Eastern flavor; combines Phrygian dominant and Locrian |
| Romanian Minor | 2, 1, 3, 1, 2, 1, 2 | Gypsy flavor; mix of Dorian and Phrygian |
| Hirajoshi | 2, 1, 4, 1, 4 | Associated with Japanese Koto music |
| In Sen | 1, 4, 2, 3, 2 | Traditional Japanese scale |
| Iwato | 1, 4, 1, 4, 2 | Pentatonic scale used in Japanese court music |
| Kumoi | 2, 1, 4, 2, 3 | Another scale from Japanese Koto music |
| Slendro | 2, 2, 2, 2, 4 | Pentatonic scale found in Java and Bali |
| Pelog | 1, 2, 4, 1, 4 | Another scale from the gamelan music of Java and Bali |
| Chinese Major | 4, 2, 1, 1, 4 | Traditional Chinese pentatonic scale |
| Chinese Minor | 3, 2, 3, 2, 2 | Another version of a Chinese pentatonic scale |
| Raga Bhairavi | 1, 2, 2, 1, 2, 1, 3 | A morning raga |
| Raga Kafi | 2, 1, 2, 2, 2, 1, 2 | Evening raga with similarities to the Dorian mode |
| Balinese | 1, 3, 2, 4, 2 | Associated with Balinese gamelan music |