When they came to Merriweather Post Pavilion, the two had been touring since March with their new album, “Sidewalks.”

They arrived with only a few hours’ sleep from the West Coast. Johnson didn’t know what songs they’d be playing, or even when they’d go on. “When you slide into a festival, there’s a lot of winging it,” he said.

The larger problem for them was that FreeFest set up like a hybrid: The pavilion was reserved for VIP ticketholders while free ticket holders were relegated to the lawn. That meant even veterans like Pavement played to smaller-than-expected crowds.

For a band like Matt and Kim, which feeds off a crowd’s energy, playing to a few is death. “That threw me off,” Johnson said. “There was a huge line of people trying to get down, but they couldn’t. I felt bad for the people who were stuck a mile away.”

There were technical issues, too. They didn’t do a sound check and just launched into their 6 p.m. set. Their ear pieces weren’t working properly, and they performed on a riser that wouldn’t stay locked down. “It was like playing on a rowboat,” he recalled.

In the end, they had to cut the set to a half-hour. Despite it all, Johnson said he appreciated the curveballs. “I like a situation where we’re put in front of a crowd that didn’t know that much about us,” he said. “We loved that challenge.”

When Matt and Kim started out, they were the quintessential party band — all exposition and little introspection. But in the last two albums, they’ve displayed a new maturity, slowing their mania to a quiet defiance.

Even when things go wrong, their approach is that anything can be fixed by slamming your drums and keyboards as loudly as possible. Just see the “Lessons Learned” video, where the two, after stripping in Times Square, fight off a pair of cops trying to stop them.

“Our attitude is always, ‘We’re still going to have fun,’” Johnson said. “As much as stuff seemed to go bizarrely, the feedback we got was super-positive.”

At Rams Head Live, they’ll play on their own terms.

“If you have something that’s bizarre to you, it takes you out a little bit,” he said. “But with our own stuff, we can be ourselves. Everyone’s going to be in front of us, and they’ll have room to dance. There won’t be a big empty-seated section. We’re not much of a sit-down band.”

They’ll stick to songs from their demos and their first two albums instead of new songs from “Sidewalks.” “When I go to shows myself and the band screams, ‘Does anyone want a new song?’ I just think, ‘I just want to hear the stuff I know and can sing to.’”

If you go: Matt and Kim perform Saturday at Rams Head Live, 20 Market Place in Power Plant Live. Baltimore duo Rapdragons play before them. Doors open at 7 p.m. Tickets are $17. Call 410-244-1131 or go to ramsheadlive.com.

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• Pictures: Recent concerts