Born in 1909, Johnny Mercer was nearly a generation younger than the giants of the golden era of 20th-century popular song. He hit his stride just when Broadway was beginning its slow decline and TV was eclipsing radio. To be sure, he was successful nearly all his life--as a songwriter, a singer and a businessman (he cofounded Capitol Records). Still, it ate at him that he never had a Broadway hit and that a lot of his best work ("One for My Baby," "Blues in the Night") was written for lousy movies. Maybe this helps explain why an otherwise lovable man was such a mean drunk, or why his songs are so drenched in melancholy. Whatever the reasons, he never seemed at home in the world.

"Portrait of Johnny," a biographical memoir by his friend Gene Lees, never stints on the backstage details--Mercer's bad marriage, his affair with Judy Garland--but as a songwriter himself, Lees knows why we should really remember his friend. At the end of his story, he recounts a conversation with a friend of the Mercer family's. "Don't you think Johnny was more than a lyricist--he was a poet?" the man asked. "No," Lees replied, "he was more than a poet, he was a lyricist." Mercer took plain old American speech and made it indelible. The words to "Skylark" or "In the Cool, Cool, Cool of the Evening" sound as if the singer just thought them up on the spot--no matter how many times you hear them. Johnny Mercer was not a genius of the American song lyric. He was the genius.