When he was in his early 20s, Copland went to Paris where he studied music with Nadia Boulanger. She was one of the most important music teachers of the time. He returned to New York in 1924. The famous conductor of the Boston Symphony Orchestra, Serge Koussevitzky, learned about Copland' smusic. Koussevitzky led the orchestra for the first performance of Copland's early work, "Music for the Theater, "in 1925. Koussevitzky also conducted Copland's "Concer to for Piano and Orchestra" in1927. This work was unusual be cause Copland used ideas from jazz music in his con cer to.