When drummer-vocalist Dean Spunt and guitarist Randy Randall, aka LA duo No Age, walked into the AV-aerie last Tuesday and started taping their T-shirts to the wall over the merch table, you could tell they were exhausted. They burn a phenomenal amount of energy onstage, and they’d already played once that night, at a free show to help promote a new indie-leaning MP3-and-merch site called Shockhound. Now they were about to play again, as the not-so-secret headliner on a bill with Soft Circle, Lichens, and Love of Everything.

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Even before No Age arrived the show was extraordinary. A crowd of maybe 150 kids, alerted to No Age’s presence on the bill by the band’s blog, the AV-aerie’s MySpace bulletin, or old-fashioned word-of-mouth, had turned up looking to go nuts, but when I walked in they were chilling out to the blissful drone of Lichens, aka Robert Lowe, and half of them were sitting rapt on the floor—in contrast to the typical Lichens set at the Bottle, where the crowd chatter is loud enough to compete with the quieter parts of the songs. Then Soft Circle, Hisham Bharoocha’s one-man act, took the stage and flipped the mood. His deep grooves, built from loops of drums and baritone guitar, aren’t far removed from the heady weirdness of his old band Black Dice, but they inspired more riotous, joyful dancing than I’ve ever seen at a show by an allegedly experimental band.

The audience is clearly prepared to freak the fuck out when No Age finally comes on, and when the band rip into their set at chest-rattling volume the entire front half of the room explodes into a mass of bouncing bodies with a mosh pit at its center. After dying out almost everywhere but the hardcore and metal scenes, where innovations like the “wall of death” have upped the odds of real injury, the mosh pit has come back to indie rock—and here it feels friendlier and more cooperative, less a tough-guy contest than a spontaneous expression of “this is so awesome let’s jump around.”

Then it’s back to a No Age song, and the crowd somehow goes even crazier. Randall crowd surfs. Hisham Bharoocha crowd surfs. The band plays “Chinese Rocks.” Spunt finally announces “One more song,” and it’s my favorite, “Teen Creeps.” Some of the people who’ve left the pit dive back in, and the mass of bodies radiates energy so contagious that everyone in the room—even the half of us who aren’t jumping all over one another—can feel it. The band decides to play one more, and it looks like they might win the endurance match. The pit’s down to half strength, and the people still left have to take two or three turns under each crowd surfer to give him a full ride.