Lotus

At its worst, so-called “jam-tronica,” that small subset of improvisational music spun around electronic and dance sounds, can be every bit as meandering as the worst guitar-based jam music, but Philadelphia’s Lotus, who plays a 9 p.m. show at the Miramar Theatre tonight, has increasingly fine-tuned its niche genre. The group’s affable new disc, Hammerstrike, released this month on the String Cheese Incident’s SCI Fidelity label, has grooves to spare, and though the group stretches these funky, cowbell-laden jams to the breaking point, they never draw them out to the point of boredom. It’s like Tortoise decided to drop their art-rock pretenses and just invite The Rapture over for a dance party.