The Sonata for clarinet, viola, horn and piano, op. 37 was composed in 1920 (at the latest). The violist Michael Balling, a friend of Johanna Senfter, wrote to the composer about the work, which he had looked through: “I have just studied your Trio [!] Sonata as a real Sunday treat and congratulate you warmly on the beautiful, warm tone you have achieved. [...] The tone colour is excellent to my taste, and can perhaps be exploited even more by adding the low notes of the clarinet in some place...