Passage: "Who's That Girl" is a song by American singer Madonna from the soundtrack album of the 1987 film, Who's That Girl. It was released on June 23, 1987, by Sire Records as the first album single. The song was later included on the two-disc edition of Madonna's 2009 greatest hits album Celebration. While shooting for the film, then called Slammer, Madonna had requested Patrick Leonard to develop an uptempo song that captured the nature of her film persona. She later added the lyrics and vocals to the demo tape developed by Leonard, and decided to rename the song as well as the film to "Who's That Girl".

Question: Madonna sung which song?
"Who's That Girl"