Altogether Birtwistle set nine of Celan’s poems to music. Universal Edition publishes Night, White and Light and Tenebrae (each of which can be performed alone) as well as three of his nine short string quartets. (The other six songs and quartets are available from Boosey [&] Hawkes). When performed together, the nine songs and nine quartets alternating as part of a single work are called collectively Pulse Shadows. The three Celan settings are slow laments; Tenebrae, in which the poet addresses God directly, is the most animated.