In Stanley Kubrick’s 2001: A Space Odyssey, the appearance of the big black monolith is intensified by strange, ominous music. Voices and instruments cautiously creep outwards from a low B-flat, nervously circling around a few notes. The music gropes its way along, spreading, bifurcating and expanding to fill the sonic space. In no time, it has grown into a complex, teeming mass of sound. This music is the Kyrie from Hungarian composer György Ligeti’s 1965 Requiem, a Latin mass for the dead written by a Jew whose father and brother were murdered in Hitler’s death camps. This Requiem is far...