you don't seem to realize that a song from iTunes and a song from RB/GH is sth. totally different - these RB/GH songs have way higher quality/bitrate and have individual streams for each instrument (which is why they are able to deactivate the instrument you are playing, if you miss a note)
and they have note charts, you know actually these people are trying to make a living by providing charts for songs
now, if you'd use "frets on fire" (freeware) on PC you'd probably be able to just use your iTunes songs (WMA/AAC) and dl free note charts users provided and play them with your PS3 guitar (I don't know if they added other Instruments to fof in the mean time) - it works, although the experience isn't on par with the real thing







