Both Ligeti and Heppener belong to the generation born in the 1920s which formed the basis for the post-war avant-garde. 'Lux Aeterna', used by Stanley Kubrick in his film '2001: A Space Odyssey', marked the installation of a new musical language. The later 'Sonata for solo viola' simultaneously evokes the polyphony of the 14th century and certain varieties of ethnic music. 'Im Gestein', a cycle of lieder to poems by Paul Celan which won Heppener the Matthijs Vermeulen Prize in 1993, was here recorded for the first time in 2008.