codebeat

Recommended Usage

• Install:

npm install codebeat

• Import:

const Codebeat = require('codebeat')

• Instantiate with voice config:

const melody = new Codebeat({  
   tempo: 128,                                            //default is 60
   instrument: 'square',                                  //default is 'sine'
   timeSig: '3/4',                                        //default is '4/4'
   loop: true                                             //default is false  
})

• Write and play music:

melody.update({notes: `
  t d4, t d_4,
  t d4, q a#5,
  q b5, q rest
`})

melody.play()

Note: Up to six audio contexts (voices) can be active on the window object. Each instance of Codebeat creates a new context.

Continue reading below to learn more about writting music in Codebeat.

Introduction

Codebeat is a javascript library that provides a simple language for music composition.

Note duration

A note's duration is the relative amount of time it is played, known as a subdivision. The names of common subdivisions are abbreviated as follows:

• ts = thirty-second
• s = sixteenth
• s. = dotted-sixteenth
• t = triplet
• e = eighth
• e. = dotted-eighth
• q = quarter
• q. = dotted-quarter
• h = half
• h. = dotted-half
• w = whole
• w. = dotted-whole

Note: 3 triplets = 2 eighths

Note pitch

A note's pitch is the name for its frequency in Hertz. D in the 5th octave is written as d5. Similarly, G-flat in the 3rd octave is g_3, and C-sharp in the 6th octave is c#6. A pitch can be between a0 and g#7, inclusive.

Basic notation

General format: [note_duration][space][note_pitch][comma]
In practice: h d5, q g_3, q c#6 etc.

Note: any amount of tabs, newlines, or whitespace can appear after the comma, but not between the duration and pitch

Repetition

To simplify the writing process, groups of notes may be assigned to variables (separated with a semicolon) and repeated notes may be multiplied by an integer value.

• Variable assignment

motif = h d5, q g_3, q c#6;
t d4, motif,
t a4, motif

• Repeat single notes

h c4 * 8, t b_3 * 3

Chords

To play multiple notes simultaneously, Codebeat provides the + operator. Doing so produces a chord constituted of the pitches provided for the specified duration. The notes within a chord must be played for the same duration.

chord = h d3 + a3 + g3;

h d3, chord,
h a3, chord

Slides

Like physical instruments, Codebeat can alter the pitch of a note over time until it reaches a second pitch. This is done with the - operator. Both notes are independent of each other, which means they may be any of the allowed durations and pitches.

slide = h e2 - z c3;

e f3, slide,
h b3, slide

However, slides cannot be chained as in the below example.

h e2 - z c3 - e f4 - h d3