Robert Schneider, the de facto leader of Apples in Stereo, the flagship of the Elephant 6 indie-pop collective, has always specialized in writing 1960s-inspired psychedelic pop tarts frosted with catchy melodies and then recording them on home analog taping equipment. Velocity of Sound, the group’s fourth album of new material, cuts through the Apples’ usual twee haze with some muscular caffeine-buzzed rock moves. The hammering intro to "She’s Telling Lies" bears an uncanny resemblance to the machine-drill opening of Hüsker Dü’s "Could You Be the One," and the raw, guitar-driven "That’s Something I Do" zips along like a ramshackle Replacements homage with Westerbergian lyrics to boot ("They think that you’re nuts for hanging out with me yeah/’Cause I don’t have a pedigree"). "Where We Meet" simmers with the kind of slow-burning psychedelic chaos usually associated with British shoegazer acts; the garage rocking "Please" is outfitted with catchy new-wavy hooks.

This harder edge notwithstanding, the Apples haven’t eschewed their retro trademarks. "Something" features a classic power-pop chorus duel between Schneider and wife/drummer Hilarie Sidney. And both "Baroque" and "I Want" are dressed in an appealing coat of vintage fuzztone guitars. Velocity of Sound is a natural progression for the band rather than a drastic step forward, but the more expansive sound should help them shake their lo-fi tag.

(Apples in Stereo play the Middle East on Sunday February 9. Call 617-859 EAST.)