Cassette culture may now seem like some quaint hipster affectation but, for a generation growing up in East Germany in the years before the fall of the Berlin Wall, it was the prime medium for underground music. Fans would smuggle in recordings of new music from West Germany on tape, while avant-garde musicians in the eastern bloc’s most repressive country could circumvent state controls over vinyl pressing plants – and avoid the watchful eyes of the Stasi – by copying their own music on to cassettes and distributing them (like samizdat newsletters) to likeminded freaks.