A BRAHAM LINCOLN DID NOT, AS FOLKLORE has it, write the Gettysburg Address on the back of an envelope. But one of the Bee Gees did revise the lyrics to "Stayin' Alive" on a British Airways boarding pass.

This intriguing snippet of songwriting history comes courtesy of Stephen Bishop, the mellow California singer best known for his 1977 hit "On and On." Four years ago, while skimming through an old photo album, he stumbled upon his rough draft for the song—and a lightbulb went on. Inspired (and prevented from playing guitar by a serious wrist injury), he began the sleuthing that would result in Songs in the Rough: Rock's Greatest Songs in Rough-Draft Form, a collection of more than 70 lyrical early efforts. "I really love pop songs," says Bishop, 42, from his L.A. home. "I wanted to see a book like this, and I figured the only way was to do it myself."

Locating drafts of Jim Croce's "You Don't Mess Around with Jim" (scrawled around his wife's budget calculations) and Paul Williams's "We've Only Just Begun" (on the proverbial back of an envelope) required major badgering. "I really had to be a pest," says Bishop. "It's not my nature to call people over and over again and say, 'Well, did you find it?' "

Bishop hasn't exactly switched careers—he has a new CD, Blue Guitars—but he does admit to developing "a thing for rough drafts, the uglier the better." His favorite find? "Heartbreak Hotel," which he traced to a dusty New York City basement. The one that got away? "The Great Pretender," which was written, in an inconvenient moment of inspiration, on a toilet seat cover. "I would love," says Bishop, "to find that."

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