fmeq8.png" alt="coscos and sinsin">

<p>If we have a spectrum B made up entirely of sines (or entirely cosines), we can multiply it by 
sin A (or cos A), add the two resulting spectra, and the (A + B) parts cancel. 
Unfortunately, in this case there are some pesky -1's floating around, so we get asymmetric or gapped spectra,
but not anything we'd claim was single side-band.
</p>

<!-- CLM CASE

<pre class="indented">
(definstrument fm (beg end freq amp mc-ratio index cr0p cr1p md0p md1p)
  (let ((cr0 (make-