Park City, Utah — Anticipation was at its peak at the Sundance Film Festival Thursday, not for Britney Spears, or Al Gore or J-Lo, who have all appeared, but for a mere screenwriter.

The scribe, however, happened to be the man who also wrote Positively 4th Street and All Along the Watchtower. Bob Dylan plays the lead in the star-studded movie, Masked and Anonymous and, it has emerged, is also its uncredited primary writer.

Dylanmania was in full force as festival director Geoffrey Gilmore introduced the film, describing it as the "centrepiece" of the festival. Then director Larry Charles came out — a large man with a bushy salt-and-pepper beard, tinted glasses and a tuque on his head — who said, "I talked to the burning bush," putting himself in the position of Moses to Dylan's God.

Finally, after the actors were introduced — Jessica Lange, Jeff Bridges, John Goodman, Val Kilmer — Mr. Dylan hopped on stage, dressed in his overcoat, tuque and a scarf, and he did a tottery run to stand next to Ms. Lange, head tilted to one side, unsmiling, as Ms. Lange reached out and put a hand on his shoulder.

As a songwriter, Mr. Dylan's career is unparalleled. He has been called the voice of his generation, from the time he wrote and sang sixties protest anthems such as Blowin' In The Wind and Masters of War. His lyrics have spawned a library's worth of commentary and interpretation in books and journalism. Even now, after 40 years, each new record continues to receive critical acclaim. Mr. Dylan in the movies, though, is a different story.

Though he's performed in two acclaimed rock documentaries (Don't Look Back, The Last Waltz) his acting has been limited to a small role in the 1973 western, <í>Pat Garrett and Billy The Kid, his own rambling miasma of home movie, documentary and fiction, Renaldo and Clara, and a role as a retired rock star in the 1986 film Hearts of Fire.

Masked and Anonymous, shot in a brisk 20 days in downtown Los Angeles, has the stiff, pretentious quality of bad amateur theatre and seems likely to join the list of bombs. Hardcore Dylan fans will recognize his favourite themes — the corruption of government, deceit of women and the need for a messiah to clean up all this mess. The film opens with a montage of images of terrorists, bomb explosions, fires and homeless people, to the accompaniment of someone singing, in Spanish, Mr. Dylan's song, I Was So Much Older Then (I'm Younger Than That Now), while the tinny sounds of a political tirade can be faintly heard.

Cut to Mr. Goodman talking loudly on the phone as someone named Uncle Sweetheart, who is involved in organizing a benefit concert for the victims of all wars. The time appears to be a police state in the near future, which may or may not be the United States. Mr. Dylan plays Jack Fate, a cult singer enlisted for the concert.

Sweetheart's office is a green trailer in what appears to be the midst of a warehouse. His partner is the scheming and beautiful Nina Veronica (Ms. Lange) and assistant Bobby Cupid (Luc Wilson). Soon, the actors begin speaking in the same, half-ironic, half-nonsensical style. When Sweetheart gets beaten up by thugs for a debt he owes, Nina asks him what happened to him: "What happened to me? How far do you want to go back?" responds Sweetheart.

Deciding he can't afford Springsteen, Billy Joel or Paul McCartney for his concert, Sweetheart decides to spring an imprisoned cult figure named Jack Fate from jail.

Jack Fate, of course, is Mr. Dylan, whose face is a frown and a squint throughout. When he is led out of the jail and told he is free, he answers: "I've felt free for a long time."

While Jack prepares for his concert, he encounters a stream of peculiar characters, each involving a cameo by a famous actor. (The list includes Cheech Marin, Giovanni Ribisi, Val Kilmer, Angela Bassett, Ed Harris and Mickey Rourke). Inevitably, Jack gets the last word, even if it's hard to understand.

When a young soldier asks about his dreams, Jack replies: "I dream about going too far and intense heat. I don't pay any attention to my dreams."

Meanwhile a newspaper editor (Bruce Dern) assigns a failed novelist named Tom Friend (Mr. Bridges) to cover the story. He lives with a woman named Pagan Lace (Penelope Cruz) who prays all the time. Tom begins following Jack around asking aggressive series of unconnected questions about Jimi Hendrix's concert at Woodstock and Janis Joplin.

"I'm on your side," he keeps telling Jack. Jack answers: "That depends on your point of view."

Clearly, there's no percentage in attempting to out-quip Jack, even if you don't know what he's talking about. Occasionally, the movie stops for a performance of a Dylan song by Jack and his band, Twist of Fate.

The plot has some Shakespearean elements. It emerges that the dictator, who is also Jack's father, is dying. Edmond, the false heir who will take the leadership, is played by Mr. Rourke, who promises to outlaw "stupidity." Mr. Harris pops up in minstrel-show blackface plucking a banjo. He was his father's favourite entertainer, but because he was strong and had the forum of the public stage, he spoke out on issues, which he now regards as a kind of suicide. Somewhere near the conclusion Jack observes: "I gave up trying to figure out what it all means a long time ago."

At the question-and-answer session after the screening, the director was on the defensive. "Go ahead and shout abuse," Mr. Charles said, though the audience proved more puzzled than hostile. When the actors (except Mr. Dylan) reappeared on stage, Mr. Charles said, "I thought they abandoned me long ago."

During the question period, an audience member asked about the two screenwriters who were credited with writing the movie.

"We don't talk about the writers," Mr. Charles said.

"If Bob Dylan wrote the script, why wouldn't he take credit?" the man persisted.

All became clear when the actors were asked why they took their roles and Ms. Lange let the cat out of the bag. "It was a chance to speak Bob Dylan's words," she said.

Unmasked, and no longer anonymous, the star had long ago left the building.