This was written by Irving Berlin in 1926 as a last-minute song for the 1926 musical Betsy
. Belle Baker introduced the song and on opening night the audience asked for 28 encores of it. At one point, Baker forgot the lyrics and Berlin, sitting in the front row, sang them to her.
It reached the charts 6 times that year and became one of the first songs heard in a talking picture when Al Jolson sang it in The Jazz Singer
in 1927. It charted in 1941 by Johnny Long, then again in 1946 by both Count Basie and Benny Goodman. Also in 1946, it was the title song of a movie starring Bing Crosby and Fred Astaire.