Jem Aswad Senior Music Editor“Combat Rock” is the Clash’s most commercially successful album, and it’s also the one that tore them apart. Although it contains their two most-popular songs — “Should I Stay or Should I Go” and “Rock the Casbah”— and made them into one of the world’s biggest bands, it’s a disjointed, confusing album, with three absolutely killer tracks, a handful of middling ones and a bunch of indulgent solo experiments.