PLAYSOUND(sfx, pan#, volume#, loop#) where loop is TRUE or FALSE. This would not break combatible at all, since loop# should only been a option of course.
Yes I are aware of SOUNDPLAYING(), but its cannot been used fora looped sound because this require very careful timing as well. And its would also chop sometimes anyway and then cutter when lopped.
For stopping the sound, simply add a STOPSOUND(sfx) command.
Also changing panning and volume on a played sound while playing a sample would been nice, but not required.
PS. Yes you can do looped music which is very nice, the only reason is I need two looped samples (one music, and one sfx).