The Clash released a single in 1978 called "Clash City Rockers" and a Casbah is a Citadel fortress within a city, so is it something to do with 'City?'
I think 4 might be "arabic". I've been fixated with the answer for a while, but I couldn't see why. Your post led me to it, Les. "Rock the Casbah" by the Clash?
Les40 and peterm...clasp becomes clash but their (classic) "rock the casbah" is a diversion, the answer is a characteristic of a casbah(in the sense "medina quarter")
Just checking back in. Is the Americanism something like THE MAN? I'm actually at a disadvantage with these, since I didn't think of CAN for the other clue; it's just so common here.