from what I understand itunes doesnt copy over the music files the same way as you find them on your computer. itunes sends them over fragmented, for security reasons maybe.
There may be others but the only other that I know of, which i use to play my music from time to time or identify/find new music is Soundhound which you can find on the app store, which I believe has a free and paid version. I have the paid version.
The app allows you to ID music as you listen/sing/hum the song while it is detecting it. it also allows you to play your music and suggest other bands or songs you may like.