I think what Mystagogue is trying to say is ... they have a virgin record store tent, and they usually have like 45 minute autograph sessions with several of the bands throughout the fest ... I've seen some pretty long lines for those, and indeed, it's a assembly line format so, I'd assume it's get your shit signed, say hi ... then "NEXT!"
Keep your eyes peeled if you know what they look like ... I've seen quite a few band folk just walking around taking in other shows.
Keep an eye out in the crowds...you'll spot all sorts of celebs & musicians. Seen MURS walking around & buying a churro last year...spotted Ethan Suplee & Juliette Lewis dancing to Spearhead a few years ago...Flea sitting beside the stage at a show or two...
Just study up on what the people actually look like and you'll be surprised who you see.