He published the authoritative catalogue of Weill's music, Kurt Weill: A Handbook (London, 1987) and, in German, edited and annotated a collection of Weill's writings, Kurt Weill: Ausgewählte Schriften, and a symposium of writings by others about Weill, Über Kurt Weill (both Frankfurt, 1975).
He created an authoritative resource on Weill's music, titled Kurt Weill: A Handbook (London, 1987), and also edited and annotated a selection of Weill's writings in German, Kurt Weill: Ausgewählte Schriften, as well as a collection of essays by other scholars about Weill, Über Kurt Weill (both Frankfurt, 1975).