In a group of 3 or more, have each person prepare a large playlist representing a wide swath of their music library. 

These mini-libraries will be randomly distributed to other participants, who will create a playlist that they believe represents them out of the other person's music (preferably leaning towards songs that they were previously unfamiliar with).

A third person will be randomly selected to receive the playlist, and they will try to guess a) whose library was used & b) who made the playlist.