how random must it be?
you can do int(random(1,5)) or use choose(1,2,3,4,5,6,7) , then convert the number in a string text and play from sounds/music folder and you place str(yourvalue) in there.
then you need to build on the number picked what audio you want to play, or have the files named like that and tell the audio to play that file using the set source i think expression or play from folder... been a while since i used it. there's different approaches let me see what i can do in 2 minutes.
Edited: 
yiuyiu6666 i think 2 minutes past ... my bad if was more than 2 here is a random audio capx