While working at the Library of Congress on Copland's autobiography, Vivian Perlis came upon parts for a movement of a string quartet among the composer's papers. Little is known about the circumstances of its composition. It was probably written as an assignment for Nadia Boulanger just before Copland returned to the U.S. from Paris in 1924. The movement is in three parts: a haunting slow section, followed by a short lively segment and a lilting finale. The Alexander String Quartet played the movement for Copland at his home in 1983, almost sixty years after its composition. He approved it for publication and for the premiere by the Alexander Quartet.