That preview period has been an fraught one. After three weeks of performances, and just days before The Frogs was to go before the critics, the production announced that Tony winner Roger Bart would replace Chris Kattan.

"Saturday Night Live" ensemble member Kattan had been playing the role of slave Xanthias to star Nathan Lane's Dionysos. A release from the show's press representative simply stated that Kattan had withdrawn from the production, and did not cite a reason for the departure. Kattan, however, subsequently gave candid interviews in which he said the dismissal had taken him by surprise, though he admitted that things had not been going particularly well for him in the rehearsal hall, with his role slowly being whittled down from day to day.

The recasting marked the reunion of Roger Bart with his Producers co-star Lane, as well as his Producers director and choreographer, Susan Stroman. Bart was Tony-nominated for the role of Carmen Ghia in the Mel Brooks musical, after having previously won the award for You're a Good Man, Charlie Brown.

Susan Stroman directs and choreographs the show, which will feature a half dozen new songs by Sondheim and mark star Lane's first attempt at writing a musical theatre libretto. According to Sondheim, Lane has rewritten "four fifths" of Shevelove's original adaptation. Lane approached the composer about taking a new crack at the script after a successful May 22, 2002, concert version of the show.

About the production, Sondheim told the New York Times, "It's not a revival. The old one was only about 40 minutes long. Nathan has really expanded it." Reports from early previews had the show clocking in close to three hours, a running time that since been shorn considerably. Nathan Lane stars as Dionysos in the musical, which is based on the Aristophanes classic. The ancient play focuses on a debate between Aeschylus and Euripides, to determine who is the greater artist. The winner of the contest returned to Earth with Dionysos to save civilization.

Sondheim (Assassins) and librettist Burt Shevelove wrote the show for a production staged in the Yale swimming pool in 1974. The story was updated to feature a debate between William Shakespeare and George Bernard Shaw and has traditionally required elaborate special effects, a large cast of actors skilled in both acting and swimming and an exhibition pool in which they perform. (No massive pool is being added into the Vivian Beaumont at Lincoln Center Theater.)

That 1974 cast included Larry Blyden as Dionysos, Michael Vale as his slave, Charles Levin as Charon, Jerome Dempsey as Pluto, Jeremy Geidt as Shakespeare and Anthony Holland as Shaw. There was also a large chorus of Yale students which included Christopher Durang, Meryl Streep and Sigourney Weaver, among others.

Two of the more known songs to emerge from the show are "Fear No More," a setting of Shakespeare verse by Sondheim, and "Invocation to the Gods and Instructions to the Audience," which was once the opening number of the score of A Funny Thing Happened on the Way to the Forum (replaced by "Comedy Tonight"), and was later heard in a revised form in the revue, Putting It Together. Also in the cast are John Byner (Charon), Peter Bartlett (Pluto), Daniel Davis (Shaw), Burke Moses (Herakles) and Michael Siberry (Shakespeare).

The production is Stroman's first musical theatre work as a director choreographer since 2001's short-lived Thou Shalt Not. Her production of The Producers is still playing at the St. James. That show was Lane's most recent Broadway credit.

Later this year, the Roundabout Theatre Company will present a revival of Sondheim's Pacific Overtures.

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Davis, a veteran of San Francisco theatre, won a Tony nomination in 2000 for his turn as a foppish, but sincere theatre producer in Broadway's Wrong Mountain. Soon after, he played Oscar Wilde in Tom Stoppard's The Invention of Love, also a Lincoln Center production.

Bartlett is known as a dependably funny high camp presence in the plays of Paul Rudnick. He most recently ended a run in Broadway's short-lived Never Gonna Dance. Burke Moses created the role of Gaston in Disney's Beauty and the Beast. Since then, the muscle-bound actor has gone on to replace Brian Stokes Mitchell in Kiss Me, Kate. Siberry's best know credit is Captain von Trapp in the 1998 Broadway revival of The Sound of Music.

A comedian as well as an actor, John Byner is a well known face from television and film. He got his start making appearances on the "Tonight" show in the early '60s and appeared on "The Garry Moore Show" and "The Steve Allen Comedy Hour." He had his own television show in 1972. He played Detective Donahue on "Soap."

The show's healthy run stretches until Oct. 10.

The songlist, according to the Playbill, runs as follows:

"Invocation and Instructions to the Audience"
"I Love to Travel"
"Dress Big"
"I Love to Travel"
"All Aboard"
"Adriadne"
"The Frogs"
"Hymn to Dionysos"
"Hades"
"It's Only a Play"
"Shaw"
"All Aboard"
"Fear No More" (lyrics from Shakespeare's Cymbeline)
"Hymn to Dionysos"

The songlist of a 2001 recording of the 1974 score ran as follows:

"Fanfare"
"Prologue: Invocation and Instructions to the Audience"
"Traveling Music"
"Parados: The Frogs"
"Hymnos: Evoe!"
"Dialogue: 'Pluto!'"
"Parabasis: It's Only a Play"
"Dialogue: 'That Was Some Banquet!'"
"Evoe for the Dead"
"Invocation to the Muses"
"Fear No More"
"Exodos: The Sound of Poets"