Peter M. Traub wrote:
> 
> Just wondering how to call macros with multiple variables.
> $MACRONAME(A'B'C), but the variable separators i've tried don't work.

You must send an example + the warning/error message output. 
Either # or ' works for me (Csound 3.53, earlier it was just # ).

#define tryit(A'B'C) #
	$A. = $A. * ($B. + $C.) 
#

$tryit(kfrq ' kfrmod ' 1.2)

Compiles (with or without the spaces around separators), 
given that kfrq and kfrmod exist in the orc.
Macro names are case sensitive. 

Good luck,