When Johnny Mercer and Harold Arlen began their collaboration in 1940, Mercer, like Arlen, had several substantial film songs to his credit, among them ``Hooray for Hollywood,'' ``Ride, Tenderfoot, Ride,'' ``Have You Got Any Castles, Baby?'' , and ``Too Marvelous for Words'' (all with Richard Whiting); with Harry Warren he did ``The Girl Friend of the Whirling Dervish,'' ``Jeepers Creepers,'' and ``You Must Have Been a Beautiful Baby.'' Mercer's lyrics are characterized by an unerring ear for rhythmic nuances, a puckish sense of humor expressed in language with a colloquial flair. Though versatile and capable of turning out a ballad lyric with the best of them, Mercer's forte is a highly polished quasi folk wit.

His casual, dreamlike working methods, often as not in absentia, were an abrupt change from Harburg's, so that Arlen had to adjust again to another approach to collaboration. There were times that he worked with both lyricists simultaneously.

Speaking of his work with Johnny Mercer, Arlen says, ``Our working habits were strange. After we got a script and the spots for the songs were blocked out, we'd get together for an hour or so every day. While Johnny made himself comfortable on the couch, I'd play the tunes for him. He has a wonderfully retentive memory. After I would finish playing the songs, he'd just go away without a comment. I wouldn't hear from him for a couple of weeks, then he'd come around with the completed lyric.''