Bad Religion were always the intense young nerds of the first L.A. hardcore wave, and these days, they look like the biggest dads on earth. Frontman Greg Graffin is a biology professor on his off-days, and he looks more like a biology professor than a punk singer. But Bad Religion have spent decades racking up an absolutely bulletproof catalog of punk rock singalongs. Newer songs like “Sorrow” and “Fuck You” sounded right at home next to their classics, and a big-but-friendly circle pit — the only moshpit of any kind I’ve seen all weekend — opened up immediately and kept going for the whole set. The band crammed 18 songs into what was supposed to be a 50-minute set, and when the festival finally shut off their sound during set closer “Fields Of Mars,” the kept playing anyway, leading a singalong without amplification. They may be dads now, but they’re still punks.