NEW YORK - Is the apocalypse closer than we think?

"Xanadu," the jaw-droppingly awful 1980 film that sank Olivia Newton-John's movie career yet couldn't kill roller disco, has been turned into a fast, funny little stage musical. Quite a transformation.

It may not start a new fad for leg warmers, headbands and the thump-thump sounds of the Electric Light Orchestra, but the 90-minute show, which opened yesterday at Broadway's Helen Hayes Theatre, cheerfully (and with camp to spare) does a bang-up job at entertainment.

Adapter Douglas Carter Beane, author of "The Little Dog Laughed," has wisely jettisoned the movie's incomprehensible story line. Still, he has kept the character of Sonny Malone, the creatively stymied Venice, Calif., artist who wants to "make all the arts converge in one place, painting, music, dancing and maybe even athletics." The obvious forum: a roller disco. The score, by Jeff Lynne and John Farrar, is taken directly from the movie.

Director Christopher Ashley has invested the musical with a sure sense of what it wants to accomplish. There is a unity of performer and purpose that is enormously ingratiating. "Xanadu" doesn't take itself seriously - except in its desire to deliver a good time. *