Und was im Dunkeln bleiben muss, op. 69, for high Voice, Oboe and Violoncello
Four songs on poems by Werner Lutz from 'Die Ebenen meiner Tage' https://editionfaedis.ch/work-info/63/Faedi%20R./und-was-im-dunkeln-bleiben-muss-op-69-for-high-voice-oboe-and-violoncello