When it comes to local post rock outfits, Grimace Federation is certainly a staple in the Philly music community pushing the boundaries in their experimental genre. Tonight at Johnny Brenda’s they’ll be celebrating the release of their latest EP On Velvet. The album is as smooth as its fabric namesake, and those velvety sounds can be largely attributed to the massive vibraphone that multi-instrumentalist Xack Xweig hauls around with a full drum kit, keyboards and his mountain bike sidekick. We had a chance to chat with Grimace vibist Xack Xweig about opening for and meeting the members of Tortoise, how you shouldn’t ask them about getting a singer, plans for a remix EP and all things Grimace. You can check out the interview here.