nds you get from this cancellation;  I can't resist adding the following
examples which come from a collection of "imaginary machines":
</p>

<pre class="indented">
(definstrument (machine1 beg dur cfreq mfreq amp index gliss)
  (let* ((gen (make-fmssb cfreq mfreq :index 1.0)) ; defined in generators.scm
	 (start (seconds-&gt;samples beg))
	 (stop (+ start (seconds-&gt;samples dur)))
	 (ampf (make-env '(0 0 1 .75 2 1 3 .1 4 .7 5 1 6 .8 100 0) :base 32 :scaler amp :duration dur))
	 (indf (make-env '(0 0 1 1 