Clearing out the archives of Sub Pop Records’ art department revealed enough hidden gems to fill a gallery, and this month’s exhibit at Art in the Age of Mechanical Reproduction does just that. “Art Debt,” presented by Philly design mainstays The Heads of State, will be opening at the chic Olde City store today for First Friday, and will remain up until August 24, presenting all manner of works produced for Sub Pop’s incomparable roster of bands. Sketches, designs, press materials, posters and album art that either became a part of the visual identity of bands ranging from Nirvana and Sebadoh to Fleet Foxes and No Age, or served a more unglamorous, functional purpose. Sub Pop is now as old as many people who frequent Art in the Age; watching music-scene old heads and young upstarts take in the show’s offerings is bound to be an eclectic, intergenerational sight. Art in the Age of Mechanical Reproduction, 116 North 3rd St., 6pm – 8pm, Free, All Ages – Alyssa Greenberg