David Mamet is said to be giving the devil his due these days, doctoring the ailing book of the forthcoming Randy Newman musical version of Faust. The show premiered last year at the La Jolla Playhouse, with Newman credited with both book and songs, and it was generally agreed that the book needed work.

But Mamet's agent, Howard Rosenstone, cautioned that nothing's official. "David's only involvement in the project right now is as friend," he said.

Besides, Mamet is currently putting the finishing touches on an original screenplay, Spanish Prisoner, which he plans to direct in the fall. "And," Rosenstone readily conceded, "there's always the possibility of a new play."

The revised Faust goes into rehearsal Aug. 22 and will be unveiled Oct. 2 at Chicago's Goodman Theatre. Depending on its reception there, plans will be made about the show coming on to New York. (The hope is for the spring.)

Michael Greif, who brought the Rent megahit to Broadway, is directing. David Garrison, late of I Do! I Do!, originated the devil's role in the first Faust and will reprise it at the Goodman--most likely with his God figure from La Jolla, Ken Page (of Cats-Ain't Misbehavin' fame).