This is the mayor who performed high kicks with the Rockettes, who dressed up as Michael Jackson with satin baseball jacket and white glove, who hosted "Saturday Night Live" and made cameo appearances in "All My Children" and "The Muppets Take Manhattan," and who made a pile of money from his best-selling autobiography.

So why not "Mayor, The Musical"?

An exuberant, witty cabaret revue celebrating the life and chutzpah of Mayor Edward I. Koch, opened tonight at the Top of the Gate theater and made political history: what other politician, up for reelection, would use a musical as a campaign tool?

Koch, who proposed the idea a year ago to Charles Strouse, composer of the Broadway hits "Annie" and "Bye Bye Birdie," mounted the stage gleefully after the production tonight, hugged and kissed the actors, and told a battery of television cameras, "I loved it."

As for his campaign, "How can it do anything but help?" the mayor asked. "It's a terrific show! It's a hit!" he said as he bounced off to a glittery cast party.

While Koch had nothing to do with the script, the mayor said in an interview, "I feel like a little kid in a candy store who's getting a sundae with ice cream and whipped cream and a maraschino cherry and chewy nuts and everything! It's wonderful! Just wonderful! Do you know many people they write revues about?

"If people hum the tunes, won't that be nice?" he said.

Meanwhile, his political opponents were not amused.

City Council President Carol Bellamy, waging an uphill fight against Koch for the Democratic nomination, remarked sourly that the show would show Koch up as a mayor "who just entertains . . . People say the musical will help him. But it does dramatize the contrast between the mayor who puts on funny hats and the mayor who forgets to attack the problems of the city. I don't think people who are trying to get to work on the subway will be particularly enthralled."

Bellamy skipped the opening for a candidates' forum in Queens; Assemblyman Herman D. Farrell Jr., who is also running for mayor in the September primary, was in Albany.

"Koch comes off as arrogant but lovable," said Jerry Kravat, one of the show's producers. "We do not lionize the mayor."

Nonetheless, while New Yorkers may recognize their mayor in a few of the musical's lines ("I'm not going to change for you. If you don't like it -- screw!"), actor Lenny Wolpe's wacky song-and-dance routine so charmed the opening-night crowd that the "lovable" overwhelmed the "arrogant."

Wolpe, 34, a theater graduate of George Washington University, confesses to being an unabashed Koch partisan, but adds quickly that his portrait of Hizzoner "isn't sugarcoated." To help Wolpe prepare for the part, the mayor's office made an hour-long videotape of clips from Koch's speeches and press conferences and invited him to watch the mayor dedicate a park to Raoul Wallenberg and meet with Japanese businessmen.

Wolpe wore a bald-pate hairpiece for the role, but aside from his 6-foot-1 height, his only resemblance to the mayor is, as The New York Times put it, his "somewhat commanding proboscis."

Koch, 60, will get 1 percent of the show's box office gross, although it is only loosely based on his book. The $240,000 production, largely financed by Sid Bernstein, head of the New York Music Co., which first brought the Beatles to America, is coproduced, along with Kravat, by Marty Richards and Mary Lea Johnson, who had collaborated on such hits as "Sweeney Todd" and "La Cage aux Folles."

Strouse said that when Koch first called him with the suggestion for the show, "I thought it was the dopiest idea I ever heard. I called friends in the theater business and nobody liked the idea." But a copy of humorist Warren Leight's recent "I Hate New York Guidebook" and, Strouse said, Leight's "antic view of New York" made him warm to the idea. Leight was hired to do the lyrics.

So far, two weeks of previews have played to packed houses. It would take another two to three months in the 300-seat theater for the backers to recoup their investment, Kravat said.

Much depends on how "in" one must be to get the distinctly New York brand of humor and the local political jokes. "I don't think this is meant for Phoenix dinner theater," Leight said.

Would the tourists, for instance, howl at the skit parodying the city's proposed $1.6 billion Times Square renovation as an "inner-city entertainment theme park" called "Manhabitat" with a Paloma Picasso graffiti gallery featuring "marvelous 'I Love New York' syringes" and "mechanical bums with simulated filth-encrusted rags?" Will they even understand the hysterical monologue on the city's absurd ritual of alternate-side parking, whereby owners double-park their cars several hours a day because of street-sweeping rules?

The show satirizes Leona Helmsley, the fastidious and much-publicized "queen" of the Helmsley hotels (when her husband, magnate Harry Helmsley, gives a dime to a bum, she exclaims, "Don't encourage him!"); John Cardinal O'Connor (who describes Koch as the "most eligible bachelor in the city of New York after me"); former mayors John Lindsay (who can't pronounce "chutzpah") and Abraham Beame; City Comptroller Harrison Goldin; and local news anchor Sue Simmons (who, in one of the funniest skits, sings her questions to get more "spark" in the ratings).

During the show, the smile on Leona Helmsley's face froze into a near grimace through the biting scene where she snubs the homeless. Nonetheless, Helmsley told reporters that she "loved the show" and that the scene "showed that we did care."

The revue took a swipe at Police Chief Benjamin Ward (for an extramarital dalliance he recently confessed to), although he came to opening night with his wife. It also poked fun at real estate developer Donald Trump, Brooklyn District Attorney Elizabeth Holtzman, lawyer Roy Cohn and even Bernhard Goetz, who is identified in the program glossary as an "electronics specialist."

In the show, Bellamy strips to boxing shorts and gloves and is given a feisty portrayal by Kathryn McAteer. At one point, Koch gloats that he has made her cry and calls her "the most uptight politician in the whole city. Oh, wait, I forgot about Holtzman." Even a ghostly Fiorello LaGuardia makes an appearance in "Mayor, The Musical" to lecture Koch on his shortcomings. (LaGuardia's own musical, "Fiorello!," was posthumous.)

City officials at the cast party agreed that the portrait of the mayor was remarkably favorable. Writer Howard Blum, one of Koch's close friends, gloated that the mayor "got away with murder" in the show.

In a lukewarm review that hit the stands just as the cast party got under way, The New York Times' Frank Rich said the musical "will offend no one, with the possible exceptions of Harry and Leona Helmsley." The show, Rich said, transforms "New York's brash archetypal political streetfighter into a cuddly, if egocentric, hero with a sparkling white smile that could rival that of Bert Parks."

The Daily News gave it a more favorable review, calling it an "engaging show about a city that, as Saul Steinberg's famous drawing suggests, is bounded by the Atlantic and Pacific . . . "

In any case, Koch-haters may shrug off the political effect by pointing out, as one city hall regular did today, that "the movie[ 'The Right Stuff'] didn't help John Glenn."