Metronome {
	var <num,<denom,<out,pattern,<isPlaying;
	*initClass {
		Class.initClassTree(Server);
		SynthDef(\click, { |out=0, freq=1200, len=0.1, amp=0.1, pos=0|
			Out.ar(out,
				Pan2.ar(
					SinOsc.ar(freq, 0, Line.kr(amp,0,len, doneAction:2)), pos))
		}).writeDefFile
	}
	*new {|num,denom,out=0|
		^super.newCopyArgs(num,denom,out).init;
	}
	init {
		pattern = Pbind(\instrument, \click, \amp, 0.1, \dur, 2/denom,
			\freq, Pseq([1200,1600,Pn(Pseq([800,1600],1),num-1)],inf),
		    \out, out)
	}
	num_ {|newVal|
		pattern.stop;
		num=newVal;
		this.init;
		if(isPlaying) { this.play }
	}
	denom_ {|newVal|
		pattern.stop;
		denom=newVal;
		this.init;
		if (isPlaying) {this.play}
	}
	play {
		pattern=pattern.play(quant: num/(denom/4));
		isPlaying = true;
	}
	stop {
		pattern.stop;
		isPlaying = false;
	}
}