var isSubset = (superObj, subObj) => {
    return Object.keys(subObj).every(ele => {
        if (typeof subObj[ele] == 'object') {
            return isSubset(superObj[ele], subObj[ele]);
        }
        return subObj[ele] === superObj[ele]
    });
};

Pattern.prototype.match = function (o, f) {
  return stack(this.filterValues(v => !isSubset(v,o)), f(this.filterValues(v => isSubset(v, o))));
}

x = s("bd sd [~ hh] sd [~ bd] [~ rd] rm bd*2")
  .bank("SequentialCircuitsDrumtracks")
  .off("1".div("[8 16]/1.2"), x => x.speed(2).gain(0.8).n(3))
  .speed(1.5)
  .juxBy(0.25,rev)
  .match({s: 'rd'}, pat => pat.crush(2).end(0.1))

y = s("bd:4(7,12,<0 2>)").gain(0.7).crush(3).speed(0.8).end(0.3)
      .fast(16/12)

stack(x,y)
  .slow(2.1).when("<0!8 1!4>", x => x.speed(saw.add(1)))