FRIDAY: >> You don’t need us to tell you any more about local heavyweights Benjy Ferree, Meredith Bragg and the Terminals, or Greenland. But tonight is Ferree’s first time headlining at Black Cat’s mainstage, so don’t forget to show up and lend your support. 9 p.m., $10. SATURDAY: >> Guitarist Nick Zinner of the Yeah Yeah Yeahs will spin a DJ set at the Rock and Roll Hotel. $10 after 10 p.m., free before. >>…