When David Bowie and Iggy Pop escaped LA to go Interrailing in the mid-70s, they heard a new European music that was largely devoid of Anglo-American rock influence: the German motorik sound, flashes of jazz, experimentation and electronica. In West Berlin, one of their favourite haunts was Kreuzberg’s Cafe Exil, a smoky hang-out for beats and intellectuals; this is its imaginary soundtrack.