you can sit outside the gates and listen to the music. Last year I got to hear Metallica’s entire set without missing a beat, I just couldn’t see them, but who cares about that.
I did the same for Arcade Fire’s set at Lollapalooza around 2009-10ish. Worked out pretty well.
Summer Camp is surprisingly easy to sneak into, as long as you know two people with wristbands that are willing to help - just have one take off their wristband and stay inside (they’re fitted quite loosely usually), and the other keeps theirs on while taking the other one out to meet you in the parking lot. For best results, wear a wristband from another year so you have something on while you’re inside. I know two people who get in this way every year. Here’s hoping they never decide to have checkpoints at the stages like Electric Forest does…