uld be obvious from these two 
functions that there is no difference in run-time computational expense or accuracy.
</p>

<!-- CLM CASE
<pre class="indented">
(definstrument pm (beg end freq amp mc-ratio index) ; "mc-ratio" = modulator to carrier frequency ratio
  (let ((carrier-phase 0.0) ; set to pi/2 if someone tells you PM can't generate energy at DC
        (carrier-phase-incr (hz-&gt;radians freq))
        (modulator-phase 0.0)
        (modulator-phase-incr (hz-&gt;radians (* freq mc-ratio)))
        