D.C. has had an embarrassment of good shows in the last seven days. Bloc Party, White Lies/Friendly Fires, Glasvegas, Cut Copy…but Friday’s Primal Scream show at the 9:30 Club was the best of the bunch. The Scream are an institution in the UK, but other than a stint opening for Depeche Mode in 1999, have never made real inroads on this side of the pond. It certainly doesn’t help that they’ve jumped from label to…