I've heard ENOUGH complaining about you being apparently UNABLE to listen to your MUSIC while you browse the PS3's system browser.
YES you can... while enjoying you music... press the PS logo button. Voila - you're back in the game. Browse your pictures away or do whatever it is you want to do. Maybe write a a letter.
Here, a video for your troubles.
that NEEDS to be in ROCK BAND, like... NOW.