FRIDAY: >> You just can’t say the D.C. music scene doesn’t care. Check out the 2-night Katrina’s Piano Fund benefit concert at Black Cat, featuring a packed line-up of local acts. Friday’s got Monopoli, the Routineers, the Washington Social Club, the Ambitions, Andy Zipf, and DJ Will Eastman. Saturday is Wooly Mammoth, The Whips, Owls and Crows, Edie Sedgwick, Rose, andDJ lil’ e. $12 for one show, or maximize your band-to-dollar ratio and pay just…