playMusicOnce(clip0, clip1)
From pinHeck Wiki
Example:
playMusicOnce('M', 'N');
Pauses the currently playing music and plays the new file (best used for short music clips or "award" jingles) Once the new file ends, the previous music fades back in and continues playing from where it left off.
One use for this is a Random Award. You might have some short music as the random award is picked, and then it will return to whatever music was playing before once done.