This song was written in 1931 and became a popular standard in depression-era America. Fabian Andre and Wilbur Schwandt composed the music and Gus Kahn wrote the lyrics. It was recorded by a variety of singers, including Nat King Cole, Michael Bublé, Bing Crosby, Louis Armstrong and Ella Fitzgerald.
When she was 15, Michelle Phillips of The Mamas & The Papas met Fabian Andre, who wrote the music for the song. Years later, when Phillips heard that Andre died in a fall in an elevator shaft, she remembered meeting him and this song came up. They decided to record it with “Mama” Cass Elliot on lead vocals. It became her signature song, and she performed it with The Mamas & The Papas and as a solo artist until her death in 1974.
Gus Kahn was a very successful lyricist in the ’20s and ’30s, writing hits like “Makin’ Whoopie,” “Ain’t We Got Fun” and “It Had To Be You.” In an NPR interview, Gus Kahn’s son Donald, who is also a composer, said: “He always tried to keep his lyrics simple. He also said that young men and women don’t know how to say “I Love You” to each other, so we say it for them in 32 bars.”
– Source: SongFacts.com