In retrospect, the Leigh for Rivera switch looks really bad. Rivera, who died in 2024, went on to become a Broadway legend though she only had a few film roles and never a lead. Leigh had barely passable singing and dancing skills, but her big dance number in “Bye Bye Birdie” looks strained, and the sequence was in questionable taste to begin with: Rosie, furious with her boyfriend for letting his overbearing mother run his life and ruin their romance, crashes a Shriners meeting and arouses the members with a sexy dance. I remember being puzzled at Leigh’s casting when I first saw the film and knew nothing about the musical’s history on stage. Now, the choice seems indefensible, ethically and artistically.

In retrospect, the performance of Jesse Pearson as the Elvis parody “Conrad Birdie,” a name inspired by the openly Elvis-imitating country western singer Conway Twitty, is offensive and inexplicable. Pearson was the understudy for the role on Broadway and handled the national tour, but he isn’t good looking, doesn’t sing especially well, is a mediocre dancer, looks out-of shape, and plays Elvis as an asshole. The cluelessness of the show’s creators, dismissing as a childish fad the artistic and cultural revolution in music that marked the Fifties is striking.

We now recognize Elvis Presley as one of the greatest American performers of all time, notwithstanding his sad end. On this viewing, I found myself wondering how much better the movie could have been if Elvis had played the parody of himself. In the movie as it was, the mockery of Conrad’s screaming fans by the parents and adults seems wholly justified. In reality, they were wrong and their kids were right, just as they were about to be when The Beatles arrived.

The father of wholesome teenager Kim (Ann-Margret), who has been chosen to give Conrad his “last kiss” on the “Ed Sullivan Show” before he joins the Army, is played by Paul Lynde as flamingly gay, as he always was. In 1963, audiences just didn’t see his speech patterns and mannerisms that way. What a strange period in the U.S.: gays were closeted, denigrated and shunned, but show business, which has always been a gay refuge, played games like this with the oblivious public. Lynde made a career of winking at his sexual orientation, notably on “The Hollywood Squares.” ( Question: “You’re the world’s most popular fruit. What are you?” Lynde: “Humble.”)

The plot of the musical was overhauled in the film. Dick Van Dyke’s character became a chemist-songwriter instead of an English teacher-songwriter, and he invents a drug that sounds suspiciously like amphetamines. Birdie’s appearance on “Ed Sullivan Show” and Kim’s big moment, plus the teen idol’s performance of Dick’s break-through song “One Last Kiss” is endangered when the Russian ballet company scheduled to lead into the “last kiss” changes its choice of number to one that is too long for the Birdie song and kiss to be included in the program, so both are cut. The problem is solved when Rosie tricks the Russian conductor to down a drink spiked with her boyfriend’s invention. He then conducts the ballet number at warp speed (film of the dancers is sped up, back when this was still considered hilarious), so the kiss and the song are slotted back into the show.

Drugging someone against his will was funny and ethical, see, because he was a Russian. We see the ballet company director waving his shoe in fury, a reference to Nikita Khrushchev’s shoe-banging antics at the United Nations. The movie came out shortly after the Cuban Missile Crisis: Russians were bad, so it was good to do otherwise bad things to them.

The movie is now best known as the film that made Ann-Margret a star. She plays Kim as an innocent 16-year-old, but in the opening and closing sequences of the movie she is just Ann-Margret, in the high energy, charismatic, seductive persona she became famous for. It is a directorial choice that undermines the integrity of the movie by book-ending Ann-Margret’s Kim with a eye-popping sex-infused performance that directly affects the “suspension of disbelief,” which would normally be essential when a director has cast a 25-year-old actress to play a virginal teen.

Nonetheless, the stunt “worked,” despite turning a wholesome family film into something else entirely. (Ironically, the real Ann-Margret is more like Kim than the “bad girl” roles she usually played in her movie career.) The actress’s next film was “Viva Las Vegas,” co-starring with the real Elvis, and giving him his best partner on screen and his best movie.

I must make one final note, unrelated to ethics. Ed Sullivan, who for 23 years hosted an iconic TV variety show on CBS that once brought all Americans together on Sunday nights, was infamously stiff as an MC and never improved. Playing himself in “Bye Bye Birdie,” however, the New York columnist is natural and relaxed, without a hint of the awkwardness he displayed on his own show. If someone can explain this, please do.