The Fleet Foxes have changed. Last summer they were good live, but they were timid and withdrawn. Saturday night at the Metro was a different band playing the same songs and a few more. A year on the road has taught the Foxes how to have confidence, and that folk songs can rock.

Opening for the Fleet Foxes was Dungen from Sweden, a psychedelic-folk-rock band who seemed surprised by the overwhelmingly positive response from the audience. They said, “You guys are here to see the Fleet Foxes, right?” before beginning their encore.

Robin Pecknold, lead vocalist and guitar player of the Fleet Foxes, quickly said that Dungen was his favorite band, which prompted another round of applause from the audience. After helping set up their own equipment and throwing several bottles of water into the audience, just like any really nice guys would do, the Fleet Foxes got started with Sun Giant, the title track off their 2008 EP.

I remember thinking last year when I saw the same band at Pitchfork that there was no way their sound or stage presence would work in an indoor venue. The songs were beautiful, but they were airy and floated right over the crowd and mixed in with the music coming off the different stages. They were quintessentially folk: nice to listen to, but not terribly exciting. It seemed to be the only atmosphere to see to them in - near the stage in the hot sun, drinking a beer and picking at nachos.

Saturday night at Metro proved my premonition to be way off. Maybe last year around this time the Fleet Foxes had more trouble making it work in a dark club, but Saturday the audience danced and bobbed their heads, while the band performed song after song off their EP and full-length release, and something told me it wasn’t just the combination of Advil and Tylenol that Pecknold was on.

They played a few new songs, and unfortunately for the band, the sound in Metro was the only thing working against them. Slightly muffled, muddy sound mixed with what seemed to be floating droplets of sticky perspiration made it hard to concentrate on lyrics and style. Their first new song, about four pieces into the set, was harmonic, poppy and psychedelic. The other ones got lost in last year’s sound, and here’s hoping the next album has a new angle to it.

Highlights of the set included the always popular Mykonos, and Your Protector, which I found to be the most powerful song played that night. With lyrics like “you run with the Devil” and “as you lay to die beside me”, the song already seems like a William Faulkner novel, but making it even more sinister was Josh Tillman’s tambourine, washed in red, and sounding eerily like a rattle snake ready to strike.

Back on stage for the encore, Pecknold asked if we, too, were ready to pass out from heatstroke, and then said, “I mean, are you ready to rock?” The crowd was indeed ready to pass out, half of them still wearing wristbands from Lollapalooza, but they laughed and then rocked on like good patrons while Pecknold belted out a solo version of Oliver Jane that filled all three levels of Metro. The final song was Blue Ridge Mountains, and it included the entire band and two members of Dungen on percussion instruments.

Overall, it was a surprisingly rocking and upbeat time. Even before considering they played Lollapalooza the day before and that Pecknold was on mixed meds, the Fleet Foxes gave a stellar performance. And yes, they were the only thing keeping the audience from passing out from heat exhaustion in that extremely uncomfortable venue.