[CM] ring-modulate

[bil at ccrma.Stanford.EDU]

It looks like rm-radians is not used in new-effects.scm, so that code
is multiplying the input samples by an oscil at rm-frequency.  This
is the same as the code in examp.scm without the envelope. ring-modulate
is just a multiply, so I think you want (ring-modulate mysnd (oscil os))
where the "os" oscil runs at whatever frequency you want (the default 
appears
to be 100Hz).  (The "radians" variable is misnamed -- this is probably
a number in Hz).