The Clash are famous for their album London Calling and their ubiquitous single, “Rock the Casbah,” which is notable perhaps for its incendiary political message—a denunciation of the Iranian ban on Western music following the 1979 revolution. But it’s “Straight to Hell,” a commemoration of immigrant struggles in the UK and abroad, that best blends political panache with a strong melody. Its Bossa Nova beat makes it one of the most accessible statements from a group that would influence many others to come. (M.I.A. sampled the song in her 2008 hit, “Paper Planes.”)