'Enigma' is the Greek word for 'riddle', 'mystery', 'secret'. At the moment of entering or leaving life, there is always a sound: the cry of a newborn baby or the last sigh of a dying person giving up the ghost. Soprano Sarah Aristidou sets out in search of the original sound in this programme, which opens with Andreas Tsiartas's Lamento Turco. The voice emerges from silence in a wordless lament on the vowel 'A'. The piece ends with a heart-rending, 'archaic' scream... Rachmaninoff's Vocalise also uses the vowel 'A'... In Schubert's Der Hirt auf dem Felsen, a shepherd sings across the valley: 'The farther my voice carries, the clearer it comes back to me.' In Messiaen's Répétition planétaire, the singer's call 'Ahi' is accompanied by the music of the planets and stars... After visiting music by Wolf and Ravel, the odyssey ends with a work by Jörg Widmann for clarinet, soprano and piano founded on the vowels 'A' and 'O'. Naturally, it is Widmann himself who plays the clarinet part, as he does in Schubert's Hirt auf dem Felsen, with Daniel Arkadij Gerzenberg at the piano.