/tune-api

A lightweight API for working with the TuneJS scale library

Primary LanguageJavaScript

TuneJS

Authors: Andrew Bernstein, Ben Taylor, Charlie Roberts

Overview: Tune.js is a web audio tuning library of microtonal and just intonation scales. Tune.js supports over 3,000 historical tunings and temperaments, ported from the vast Scala tuning archive via the Microtuner files compiled and documented by Victor Cerullo.

Demo: Microtonal Piano

List of Tunings: Tuning Archive

Example Tunings

Name Description
ji_12 Basic just instonation with 7-limit tritone
harm30 First 30 harmonics and subharmonics
pyth_31 31-tone Pythagorean scale
ptolemy Intense Diatonic Syntonon, also Zarlino's scale
couperin Couperin modified meantone
helmholtz_pure Helmholtz's two-keyboard harmonium tuning untempered
partch_43 Harry Partch's 43-tone pure scale
johnston_81 Ben Johnston's 81-note 5-limit scale of Sonata for Microtonal Piano
young-lm_piano LaMonte Young's Well-Tempered Piano
xenakis_chrom Xenakis's Byzantine Liturgical mode, 5 + 19 + 6 parts
slendro Observed Javanese Slendro scale, Helmholtz/Ellis p. 518, nr.94
harrison_5 From Lou Harrison, a pelog style pentatonic
malkauns Mode of Indian Raga Malkauns, inverse of prime_5

How to Tune.js, a Quick Start Guide

Download tune.js and include it in a script tag at the top of your page.

<head>
	<script src="tune.js"></script>
</head>

Create a Tune.js instance.

var tune = new Tune();

Load your scale of choice with the loadScale('scale-name') method.

tune.loadScale('mean19');

Set the root frequency that you'll be working with. This sets your scale to the key of A 440

tune.root = 220

Pass scale degree numbers to the note() method. By default, note(degree) returns the corresponding frequency in Hertz. You can use note() to set the frequency of an oscillator.

osc.frequency.value = tune.note(2);

Optionally, pass an octave in as a second parameter. This will return the frequency for the third note in the scale, one octave down.

osc.frequency.value = tune.note(2,-1);

Properties

Tune.mode.output

Set the output mode of tune.note(). Choose between

  • frequency: tune.note() will return a hertz value, e.g. 392.43834 for a pure G4 over C4
  • ratio: tune.note() will return a ratio value, e.g. 1.5 for a pure G over C
  • MIDI: tune.note() will return an adjusted MIDI pitch, e.g. 67.0195 for a pure G4 over C4
// Set the output mode to 'ratio', e.g. the ratio 3/2 will output 1.5
tune.mode.output = 'ratio';

The default output mode is 'frequency'. Currently the only available input mode is 'MIDI'.

Tune.scale

Read only. An array containing the ratio values of the current scale loaded with the loadScale() method.

// Returns the length of the current scale
var scaleLength = tune.scale.length;

Tune.root

Sets the scale's root frequency.

//sets the base (tonic) frequency to 200 Hz
tune.root = 200;

Methods

Tune.note(scale-degree-# [, octave-#])

Returns a microtonally tuned note value for any scale degree input. By default, Tune.note returns a frequency value in hertz.

// This will return the frequency for 7th scale degree of our scale
var note = tune.note(7)

Depending on Tune.mode, the Tune.note method may return a frequency value in hertz (default, e.g. 392.43834 for a pure G4 over C4), a ratio value as a float (e.g. 1.5 for a pure G over C), or a MIDI float value (e.g. 67.0195 for a pure G4 over C4). See Tune.mode.

An optional second argument lets you specify what octave to be played (i.e. -1 for one octave down, 1 for one octave up).

Additionally, tune.note() automatically wraps scale degrees that are out of range, so that tune.note(8) in a 7 note scale will return the second scale degree, one octave up. Therefore, given a 7 note scale, tune.note(8) is equivalent to tune.note(1,1)

Tune.chord([array-of-scale-degree-#s])

Returns an array of note values. Like Tune.note(), Tune.chord() returns values according to the current output mode (Tune.mode).

// returns a three note chord with the specified scale degrees
var myMicrotonalChord = [60,67,71];
tune.chord(myMicrotonalChord);

Tune.search("string")

Searches through the scale archive for scales that match the query.

//returns an array of scale names that contain the word "partch"
tune.search("partch");

BigP BigZ Partch

License

Tune.js is licensed as open source software under the MIT license, Archive copyright 2003-2010 by Victor Cerullo