On-stage, Bye Bye Birdie played like a champion. Though it was hardly a great musical, it was deceivingly well crafted. Unfortunately, the changes wrought by screenwriter Irving Brecher and director George Sidney damage the piece's structure and ultimately make the film entertaining but little more. Greater emphasis is placed on the secondary characters played by Ann-Margret and Bobby Rydell, the Spanish ethnicity of Janet Leigh's Rosie (vital to the conflict between her and Maureen Stapleton's character) is essentially eliminated, and two ridiculous and pointless subplots -- one involving a drug that speeds up metabolism and one about the Moscow Ballet's appearance on The Ed Sullivan Show -- are added to no positive effect. Director Sidney takes an overly cartoonish approach (exemplified by silly animated chalk drawings during "Put on a Happy Face") that takes the reality out of the movie. Fortunately, the cast and the score make up for a lot of the flaws. Ann-Margret is a wonderful mixture of kittenish innocence and sensuality, and Dick van Dyke is engaging and amiable. Janet Leigh is merely adequate, but Paul Lynde and Maureen Stapleton are quite amusing. Onna White's choreography is lively, and such numbers as "The Telephone Hour" and "A Lot of Livin' to Do" sparkle. The 1995 TV remake was more faithful to the source material, although it has its own shortcomings.