Example #8: Audio - A Simple Chip-Tune
One way to play a simple melody…
Notice that we’ve chosen to use a square wave for our oscillator so that we can get the authentic 8-bit, bit tune, style of sound?
var context = new (window.AudioContext || window.webkit.AudioContext)();
var freq = {
'c4' :261.6256,
'c4#' :277.1826,
'd4' :293.6648,
'd4#' :311.1270,
'e4' :329.6276,
'f4' :349.2282,
'f4#' :369.9944,
'g4' :391.9954,
'g4#' :415.3047,
'a4' :440.00,
'a4#' :466.16,
'b4' :493.92,
'c5' :523.28,
'c5#' :554.40,
'd5' :587.36,
'd5#' :622.24,
'e5' :659.28,
'f5' :698.48,
'f5#' :740.00,
'g5' :784.00,
'g5#' :830.64,
'a5' :880.0000
}
for (i in D = ['e5',, 'e5',, 'e5',, 'c5',, 'e5',, 'g5',, 'g5']) {
console.log(i);
var oscillator = context.createOscillator();
if (D[i]) {
onended = function() { console.log('Note has stopped playing'); }
oscillator.connect(context.destination);
note = D[i]
oscillator.frequency.setValueAtTime(freq[note], context.currentTime);
oscillator.type = 'square';
oscillator.start(i * .1);
oscillator.stop(i * .1 + .1);
}
}