kewl, the one which turned me right on to chuck was this one. the best thing about chuck is the control it gives you over time and events and this hits the nail

Code:
      // impulse to filter to dac
      Impulse i => BiQuad f => dac;
      // set the filter's pole radius
      .99 => f.prad;
      // set equal gain zero's
      1 => f.eqzs;
      // initialize float variable
      0.0 => float v;

      // infinite time-loop
      while( true )
      {
          // set the current sample/impulse
          1.0 => i.next;
          // sweep the filter resonant frequency
          Std.fabs(Math.sin(v)) * 4000.0 => f.pfreq;
          // increment v
          v + .1 => v;
          // advance time
          100::ms => now;
      }
the complete code and background is about half way down this page, give it a try although you may well have already seen it
http://chuck.cs.princeton.edu/doc/learn/tutorial.html

try making that in logic