When he heard that Paul Whiteman was looking for singers to replace the Rhythm Boys, Mercer applied and got the job, ``not for my voice, I'm sure, but because I could write songs and material generally.'' While with the Whiteman band Mercer met Jerry Arlen. He had yet to meet Harold Arlen, for although they had ``collaborated'' on ``Satan's Li' l Lamb,'' Mercer and Harburg had worked from a lead sheet the composer had furnished them. The lyric, Mercer remembers, was tailored to fit the unusual melody.

Mercer's Whiteman association brought him into contact with Hoagy Carmichael, whose ``Snowball'' Mercer relyriced as ``Lazybones,'' in which form it became a hit and marked the real beginning of Mercer's song writing career. After leaving Whiteman, Mercer joined the Benny Goodman band as a vocalist. With the help of Ziggy Elman, also in the band, he transformed a traditional Jewish melody into a popular song, ``And the Angels Sing.'' The countrywide success of ``Lazybones'' and ``And the Angels Sing'' could only lead to Hollywood, where, besides Harold Arlen, Mercer collaborated with Harry Warren, Jimmy Van Heusen, Richard Whiting, Walter Donaldson, Jerome Kern, and Arthur Schwartz. Mercer has also written both music and lyrics for several songs. He may be the only song writer ever to have collaborated with a secretary of the U. S. Treasury; he collaborated on a song with William Hartman Woodin, who was Secretary of the Treasury, 1932 -- 33.