Ingeborg Hallstein is a German coloratura soprano, known for the purity and range of her voice. She had an international career as a guest singer on the opera houses of Europe and was a member of the Bavarian State Opera from 1961 to 1973. Her signature roles were the Queen of the Night in Mozart's Die Zauberflöte and Zerbinetta in Ariadne auf Naxos by Richard Strauss. She created roles including Scolatella in Henze's König Hirsch.

The Bassarids is an opera in one act and an intermezzo, with music by Hans Werner Henze to an English libretto by W. H. Auden and Chester Kallman, after Euripides's The Bacchae.