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“Rod wrote four of the nine tunes on the album, including the one that kicks off the "slow side." "Tonight's the Night" is a song of seduction, filled with barely restrained, gleeful anticipation. "It's as erotic as 'Je T'aime,'" wrote one critic. "The string background and tenor sax solo are as romantic as dinner by candlelight." The track ends with breathy female moans, a sexy voice purring in French. That unbilled cameo was provided by Rod's girlfriend at the time, Swedish actress Britt Ekland.

"Tonight's the Night" was released as a single in the fall of 1976, and immediately ran into controversy. Many programmers objected to phrases in the song, which described a girl losing her virginity. Some tried to tape the tune and hack out offensive lines like "Angel, spread your wings and let me come inside." Others just banned the record completely. Even in Europe, it received spotty air play.

However, enough stations did play it to create a demand, and after a few weeks, most radio people were forced -- by listener request -- to air the song. In October, it entered the national pop charts, and by November it was the number-one single in the country. It stayed there for seven weeks -- longer than any other record in 1976.

Rod Stewart: “Tonight’s the Night” (1976)