COLUMBIA, MD: Virgin Mobile FreeFest 2013 at Merriweather Post Pavilion. September 21, 2013. ? Brandon Wu / for the Washington City Paper.

This year’s Virgin Mobile FreeFest felt a bit different from the previous versions. The proliferation of dance acts (like Skrillex last year, DJs Kaskade and Pretty Lights played the West Stage rather than the Dance Forest, which caused multiple mass migrations of EDM fans back and forth across the festival grounds), the lack of a hip-hop artist, the presence of a big-ticket mainstream performer (Robin Thicke, whose performance was as polished, professional, and slightly greasy-feeling as one would expect) and, oh yeah, the rain, all set the festival’s fifth incarnation a bit apart, for better or worse.

That didn’t stop 50,000 fans from gathering at Merriweather to see these acts, de facto headliners Vampire Weekend, buzz artists like Chvrches and Sky Ferreira, and more. The sky started opening up in earnest before MGMT‘s set, causing a huge swell of people to try to take shelter in the pavilion. The rain didn’t scare off too many fans, though, at least not until the downpour really started after Vampire Weekend got rolling to the biggest cheers of the day. What’s an outdoor festival without a little mudsliding?

Check out photos of the bands in the full slideshow.