Turns out, even a J Mascis "acoustic" show involves a lot of guitar pedals. Playing to a packed crowd Saturday night at 7th Street Entry, the Dinosaur Jr. frontman stuck to his acoustic Martin six-string all night, but he kept things electrified with sporadic roars of distortion and squelching solos.

The 90-minute set actually got a little messy and guitar-wonky at times. He and opener Kurt Vile were hit-and-miss trying to match up their different guitar sounds when Vile came out mid-show to accompany Mascis on two songs from his new Sub Pop album, "Several Shades of Why." The best moments were actually the softer ones, especially "Get Me" (played early in the set) and "Flying Cloud" (toward the end). Some of Dinosaur Jr.'s best songs bookended the show, starting with "Thumb" and ending in the encore with "The Wagon" and "Little Fury Things." The quirky, mumbling Mascis was more congenial than usual, smiling when a pair of audience members claimed he changed their lives. "I hope for the better," he said. The strangest thing Mascis did was cover an Edie Brickell & the New Bohemians song, "Circle of Friends." He explained the selection with a story about how Dinosaur Jr. drummer Murph often drove the van (and thus picked the music) in the early days of the band. "It was usually Zappa," Mascis recalled, so when Murph changed it up with Brickell one day, "I sorta got used to it."

Vile's opening set with his band of hairy gentlemen, the Violators, was short and a bit tepid and underwhelming compared to the vibrancy of their new album, but their sharp hooks poked through the Velvet Underground-ian haze. Among the standouts was the warped and acidic but damn elegant "Ghost Town" in the middle of the set. And unlike Mascis, Vile didn't have to explain his choice of covers: Springsteen's "Downbound Train," which ended the show with an anthemic climax.