How to use it

var Tick = requrie("bpm-tick");
var b = new Tick(128);
b.register('beat', function (x) { console.log("bam");   });
b.register('bar' , function (x) { console.log("badam"); });
b.play();

It uses Date so it shouldn't drift (aka. it won't fall out of tempo). It's not guaranteed to be 100% precise on the note though.

Available callbacks

You can register any of these:

Word key    Power key     Number (res. available)

sub         1/64          0
div         1/16          1
beat        1/4           2
bar         1             3
word        4             4
verse       16            5
song        64            6

Registering beat, 1/4, and 2 are exaclty the same thing. Registration overwrites.

Resolution

By default, resolution 2 is used. You can set your own resolution with

var b = beat(128 [, resolution]);

where resolution is an integer from 0 to 6.

At resolution 2, only callbacks for beat (1/4) and longer are called. To get sub (1/64) resolutions to be be called, you have to use resolution 0. (See table above)

Other stuff

b.on is an alias for b.register.

b.devlog = true will log numbers.