Question: What was the name of the period instrument ensemble that was formed in the 1950s by the conductor with whom Elisabeth Kulman recorded Beethoven's "Missa solemnis"?
Sentence (from "Elisabeth Kulman"): She recorded Lieder by Mussorgsky, Bach's "Christmas Oratorio" with Peter Schreier and Beethoven's "Missa solemnis" with Nikolaus Harnoncourt.
Relevant evidence: Yes