"Who's the black private dick/that's a sex machine to all the chicks" are lyrics from which 1971 US film?

The "Theme from Shaft", was written and recorded by Isaac Hayes in 1971. It is the soul and funk-styled theme song to the Metro-Goldwyn-Mayer film "Shaft" (1971). The theme was released as a single (shortened and edited from the longer album version) two months after the movie's soundtrack by Stax Records' Enterprise label.

The "Theme from Shaft" went to number two on the Billboard Soul Singles chart (behind "Inner City Blues (Make Me Wanna Holler)" by Marvin Gaye) and to number one on the Billboard Hot 100 in the United States in November 1971. The song was also well received by adult audiences, reaching number six on Billboard's Easy Listening chart.

The film's director, Gordon Parks, also had a hand in composing the theme, describing the character of John Shaft (the "black private dick/who's a sex machine/to all the chicks") to Hayes and explaining that the song had to familiarize the audience with him. Hayes recorded the rhythm parts on the theme first, scored the entire rest of the film, then returned to the theme song.

In the song, Hayes calls Shaft "a bad mother—;" before the backup singers (one of whom is Tony Orlando and Dawn's Telma Hopkins) interrupt the implied profanity with the line "Shut yo' mouth!"

The song was considered very racy for its time. As late as 1990, censors at the Fox Network thought it too risqué to be sung on "The Simpsons" (until it was pointed out that the song had been played on television before).