O Pioneers! is an American opera in two acts by composer Barbara Harbach, set to a libretto by Jonathan Yordy. It is based on the 1913 novel by Willa Cather. Harbach became enamored with Willa Cather's works when commissioned by the Central Wisconsin Symphony Orchestra to write a symphony based on Cather's 1922 novel One of Ours. When given the opportunity to compose an opera, she chose O Pioneers! because she has "always been drawn to stories about strong women." Harbach adds that Cather's story "has all the elements that an opera needs: long-term loving relationships, sibling rivalry and murder."[1]
Harbach composed O Pioneers! over a period from February 2008 to May 2009. She rendered the orchestration entirely on a computer. During the world premiere production's rehearsal period (late September to early October 2009), she made cuts to the piece for length, and added necessary interludes for scene changes and preludes before each Act.[2]