The song "The Impossible Dream" is from which Broadway musical?

The song "The Impossible Dream)" is a popular song composed by Mitch Leigh, with lyrics written by Joe Darion. It is the most popular song from the 1965 Broadway musical "Man of La Mancha" and is also featured in the 1972 film "Man of La Mancha", directed by Arthur Hiller, starring Peter O'Toole.

The complete song is first sung by Don Quixote as he stands vigil over his armor, in response to Aldonza (Dulcinea)'s question about what he means by "following the quest".

The musical, "Man of La Mancha", tells the story of the "mad" knight Don Quixote as a play within a play, performed by Cervantes and his fellow prisoners. The knight , Don Quixote, is awaiting a hearing with the Spanish Inquisition. The work is not and does not pretend to be a faithful rendition of either Cervantes' life or Don Quixote.

According Miguel Álvarez-Fernández and several other musicologists, the original 1965 Broadway production ran for 2,328 performances and won 5 Tony Awards, including Best Musical. The musical has been revived 4 times on Broadway and is one of the most enduring works of musical theater. The principal song, "The Impossible Dream", is now a very popular standard.