THE KINGDOM of rock'n'roll includes many royal personages: Elvis Presley, "The King"; Aretha Franklin, "The Queen of Soul"; and Prince, one of the latest to don a crown. Paul McCartney, who wrote the screenplay and stars in the rock musical "Give My Regards to Broad Street," should be awarded a new title -- "Sultan of Smarm."

What do you do when your ego outgrows the generous boundaries of rock'n'roll? Take a hint from Paul. String about 90 minutes worth of videos together, re-record some old hits, brush up on your lip-synching and good-guy appeal . . . Voila! A two-hour paean to yourself. Tack on a witty title (Beatles are famous for their puns, you know), invite some kindred spirits in for the fun (Ringo Starr, Linda McCartney), and you have "Give My Regards to Broad Street."

The story line of "Broad St' is based on a dream McCartney has in the back seat of his limousine. What if the master tape for Paul's new album disappears! What if an evil businessman plots to foreclose on Paul's recording company unless the tape turns up by midnight! What if Paul saves the day at 11:59 p.m.! Sure it's unbelievable. What the heck? When your whole plot is a dream, you can get away with stuff like that. Right?

The story line isn't that important to those who made "Broad Street" anyway. All that's essential in this movie is seeing Paul: Paul in a new wave outfit; Paul's hands as they play a multitude of instruments; Paul driving his hotrod around London; Worst of all, Paul in Victorian togs, picnicking with a 19th-century Ringo and their ladies. As an added bonus, we hear Paul in a soundtrack that mixes remakes of Beatle classics and Paul's later hits with "Wings." McCartney has assembled a strong back-up group for these tunes, and fans of his music will be well-pleased. Beatle devotees are liable to wonder why he tampered with perfection.

The late Sir Ralph Richardson as "Jim" makes his final screen appearance in "Broad Street." In a brief scene together, Paul says to him, "Thanks, Jim, I've got to be off." Jim replies, "Paul, you've been off for years." Hmmmm.