lp.js

for(var i=0;i<client.numDevices;++i) {
    var d = client.deviceAtIndex(i);

    if(isLaunchpad(d)) {
        d.reset();
        
        for(var i=0;i<8;++i) {
            for(var y=0;y<8;++y) {
                d.wait(.05)
                .sendMIDI([0x90, (y*16)+i, Math.floor(Math.random() * (127 - 20 + 1)) + 20])
            }
        }
    }
}