 Margaret Hillis established a Tanglewood Alumni chorus in 1950, and her conducting career was furthered by Fritz Reiner in Chicago.Aaron Copland, who was a student of Nadia Boulanger in the 1920s, helped Caldwell develop at Tanglewood in the 1950s.Copland chose Boulanger to be his composition instructor, and he became leader of the composition department at Tanglewood.