I don't know if anyone has done this before but here is what I propose. Post a link to the bio of your character, and then post a link to to the song that should be that characters theme song. You can also post different songs for specific emotions or scenarios. For example, you can have the Star Wars theme song as your general theme and then have the Matrix lobby shootout song for your battle theme. That is just an example though, you don't have to have anything as cliche as that. Try and avoid choosing songs that others have used.
This is all to help people flesh out their characters. Music is better at portraying emotions than words.