One is a song from the musical A Chorus Line.
Director Michael Bennett explained his view regarding the song's inception and placement within the show:[1]
CityBeat described the song as "the show’s greatest emotional wallop".[2] The Davis Enterprise dubbed it the show's "signature tune".[3]
In 1976, the Brady family performed the song in the pilot episode of The Brady Bunch Variety Hour.
On Sesame Street, it was covered by 10 Muppet numbers in a chorus line.
The Simpsons parodied the song in the episode "Treehouse of Horror V".
Catherine Zeta-Jones performed the song, with modified lyrics, in dedication to her husband Michael Douglas during the 2009 AFI Lifetime Achievement Award Ceremony.