Last month, "On the Download" premiered the first MP3 from Dirty Bombs, a Voltron-esque local supergroup featuring members of Televandals, the Luxury, and Conservative Man. Their collective mechanical roar persists here with "In Every City," a blistering post-millennial rock joyride that opens like an explosion, breaking at once into its electro-disco chorus before bouncing along through seas of fuzzed-out synths and thumps while maintaining a vicious alt-rock edge.

In 2010, perhaps the only proper way for a new local supergroup to announce its arrival on the Boston scene is to roll hard into the monthly Rock n’ Roll Social at the Model Café. That’s what Dirty Bombs did last night in Allston, passing out a few fresh-out-da’-oven demos to get us all excited over their debut show next week at soon-to-shutter, soon-to-be-reborn-as-a-geographically-mislabeled-music-hall, Harpers Ferry