Complex sentence: The first performance of "Der Schatzgräber" (Frankfurt, 21 January 1920) was the highpoint of his career, and in March that year he was appointed director of the Hochschule für Musik in Berlin.
Split into simpler sentences: The first performance of "Der Schatzgräber" (Frankfurt, 21 January 1920) was the highpoint of his career. In March that year he was appointed director of the Hochschule für Musik in Berlin.