Play-sound-from-file
From FreeSpace Wiki
Plays a sound file located in either the /sounds or /music folders. The SEXP needn't include the file extension, neither its location. You can set this SEXP to loop the sound file by giving a nonzero number as its second value.
Example:
(play-sound-from-file "BattleMusic01" 1)
Only one sound can be played by this SEXP at a time.
