The ads call it "The Best Musical Ever," a judgment that is at least debatable. But as of Thursday, no one can dispute that A Chorus Line is the longest-running Broadway show ever. This week, almost eight years after it opened, Michael Bennett's Broadway show about dancers auditioning for a Broadway show will celebrate its 3,389th performance in suitably grand style. The current company of A Chorus Line will be joined by not only the original company but also the national touring company, the international company, the two bus-and-truck companies, the Las Vegas company, and members of the foreign companies -- each group performing a segment of the show, and all of them appearing in the finale, 350 dancers strong.

The preparations have been something of a logistical nightmare, not to mention costly. "My guess is that this event will cost over half a million dollars," Mr. Bennett was saying one afternoon recently in his comfortable, sunlit office on lower Broadway. "The show only cost $256,000 to do Off Broadway, and I rehearsed for a year!" In the spirit of the show itself, though, the record-breaking performance will pay tribute to all the dancers who have contributed to the making of A Chorus Line and, by extension, all the dancers who are the backbone of the American musical theater. The success of the show, in turn, is a tribute to the process of making theater.

In the year and a half that A Chorus Line developed from a midnight talk session to an extended workshop in a rehearsal room to an Off Broadway sensation to a certified Broadway smash, Mr. Bennett and his collaborators probably never imagined they were inventing new guidelines for making musical theater. But the workshop process, which for decades had been used to create new work only by such experimental theater artists as the Living Theater, the Open Theater, and Joan Littlewood's Theater Workshop, has increasingly become not only a sensible but an essential step, artistically and financially, in mounting a Broadway musical.

"What workshops mean is you have the opportunity to test material on actors," Mr. Bennett said. "Workshop gives the writers time to rethink and rewrite material. No one's right all the time. Workshop allows you to be wrong. Then you fix it, and keep fixing it. One day you say, 'Gee, this is pretty good, it's time to show it to people.' Sometimes it's never pretty good, and if you're smart you abandon it in workshop. A workshop costs a hundredth of what it costs to do a Broadway show. Dreamgirls, which had four workshops, cost me about $150,000. The show cost $3.5 million to produce. Do you know how much easier it is to raised $150,000 to do a workshop? That means anybody with an idea for a musical could really employ a lot of out-of-work actors and could try things. It is, I think, the solution to the problem of the musical theater.

"It's one thing to have the script and have everybody believe in you and try to raise $3.5 million," he went on. "It's another thing to have a show on its feet and to be able to say, 'Do you like this? Would you like to be an investor?' The workshop process has enabled a lot of shows to be done that otherwise would be regarded as too risky or too dangerous. Like Nine. You have to understand, when you go to producers and talk about a musical that doesn't have stars in it, they tend to be very short-sighted. They think it's got to have elements of something that was successful before. You see that in films all the time -- you're going to see 20 Flashdances over the next few years. I'm not blaming the businessmen, they have their job. I'm saying it's only the artists who are trying to do something different."

The workshop process has also proved valuable in developing younger artists. As an example, Mr. Bennett mentioned his former assistant choreographer Graciela Daniele, who is directing the new Marvin Hamlisch- Carolyn Leigh musical Smile. "If that started as a $3.5 or $4 million musical, Graciela might not have gotten her first opportunity to direct," he said. "But she got to do the workshop, and I think she's going to be a very good director. All the choreographers and directors used to train in stock, but there is no stock anymore. Now you have Tom Jones playing for a week followed by Liberace. So there's no training ground, and you cannot possibly be the leader of something as complicated as a Broadway musical unless you have done a number of them before and learned what everybody does.

"It always interests me when I read that an English director who's done great work at the National or whatever is signed to do a Broadway musical. I always think, 'Poor thing.' First of all, he's going to do it in four weeks, he's going to have to talk to his set designer and costume designers and all that prior to working on the show, and he doesn't really know American actors when he comes over and has to hire his cast. Then he's got to be creative on top of all the pressure of learning how to organize a musical. He'll never, never make it."

Michael Bennett learned to organize a musical by coming up through the ranks from teen-age chorus boy and assistant choreographer to producer and director. Along the way he has picked up six Tony Awards as director and choreographer, ranging from Stephen Sondheim's Follies in 1972 to last year's Dreamgirls, not to mention a reputation as a musical theater savant that he finds laughable.

"I believe there's a place for every kind of musical on Broadway, including revivals, which I hope I never do as long as I live," said Mr. Bennett, who recently turned 40 and discarded his scruffy beard and ubiquitous baseball cap. Though he had forsaken his usual jeans and sweatshirt to be photographed in a dapper suit, he still spoke with the gum-chewing casualness of a street-wise youngster. "Broadway can't be all people who are pushing forward the musical theater. There's room for family musicals, old-fashioned musicals, adventurous musicals, rock musicals. Underline rock musicals.

"Theater has to keep pace with the '80s or it will become like opera, an elitist art form. That's why we've got to get Billy Joel to write for Broadway and Jimmy Webb. We lose an awful lot of talent to the movies and recording careers. I think the future of the theater, for the next few years, is in small houses, an enlarged Off Broadway situation. It's the only place where new people are going to get a chance."

His own plans for the next few years include three musicals currently in development. One project, which has a book by Treva Silverman, a writer for The Mary Tyler Moore Show, is a musical about sex. "Does that sound like Oh! Calcutta!? It's really about relationships," said Mr. Bennett, "but people are much more interested when you say it's about sex." Another is a musical about fathers and sons being written by Louis LaRusso 3d and based on Mr. Bennett's relationship with his own father.

The third musical Mr. Bennett has in mind is the life story of Ziegfeld Follies star Ruth Etting, which has previously served as the basis for the movie Love Me or Leave Me featuring Doris Day and James Cagney. Mr. Bennett would like to have Ann-Margret play Ruth Etting in which would be, for him, yet another backstage musical. "I think I am now the king of backstage musicals, and you know what? I like it," he said. "I hate being typecast, but I realize people are happier when I'm doing backstage musicals, and the truth is I am, too. I love Gypsy. I like Bandwagon and Singin' in the Rain. I like musicals about how musicals are made."

What he doesn't like are revues. "Cats is a revue. I don't believe in that," he said. "I try to do musicals that are much more like plays. I like things that have a story. It's all storytelling, right? It has to have a beginning, a middle, and an end. What makes it a musical is the style, the tone of it, and the devices used.

"For instance," he went on, "My One and Only has a definite style from an earlier period of musical comedy. There are certain rules that go along with that style in terms of how you tell the story, the way you build numbers, the way you end numbers, everything. A modern musical has different rules, but it's still storytelling. In the old-fashioned musical, they finish a number with their arms raised in the air, they stare at the audience, the audience applauds. The audience is acknowledged as being at a musical, whereas one of the dangers of the modern musical is that the audience is somewhat distanced, not acknowledged, more like a voyeur.

"Tone is about how serious you want to be. Do you want a G rating like Annie, or an R rating like A Chorus Line? Are the people going to talk like people talk today, or are they going to talk in a way that's nice for the musical comedy stage? What's the other word I used? Oh yes, the devices, the theatrical devices. What I do is very dependent on the design elements. Every time a number builds, there's a light change. Scenery can make or break a show. People think that Dreamgirls has no set, but those revolving light towers are very important. They define the space; they tell you we're on stage or off-stage or we've moved or we are traveling. They are almost like the narrator. And then they start closing in. The dressing rooms get bigger but there are more pieces in them. There's more of a feeling that those girls are trapped by their success."

One never gets the feeling that Michael Bennett is trapped by his success. His independence from the usual creative and financial pressures of making musical theater has been further solidified since he bought an eight-story building at 890 Broadway five years ago and spent a lot of his earnings from A Chorus Line converting it into rehearsal studios, which he rents when he's not using them for his own workshops. The American Ballet Theater and the Eliot Feld Ballet are permanent residents, while the rehearsal studios currently house such forthcoming productions as Doonesbury, The Rink, and the movie Cotton Club.

"What I wanted to do is encourage theater," said Mr. Bennett, who has no artistic involvement with the shows that rent space in his building. "I believe in the musical theater. I was very happy that La Cage aux Folles was a hit. I hate it when I spend evenings with my friends, and they're sitting there complaining about not working. I'd rather see everybody working. Also, it's wonderful to work in this building because when you go into a room where you have problems with your writers and problems with your actors, you know that across the hall Hal Prince is having problems with somebody else. There's much more a feeling of community, the feeling that what we do is not so special.

"Because of Chorus Line breaking the record, I'm being treated much more seriously than I like. To me, this whole thing is a chance nine years later to get some perspective and to say thank you to a lot of people. But I'm really torn. Although I don't really believe in awards, I can't fight the fact of its being the longest-running show ever. At the same time, it's more accomplishment than I want at this point in my life. I don't want to feel that secure. The Actors Fund wanted to give me their award for lifetime achievement, and I said don't give it to me, I don't want it. I'm only 40! This isn't my life's work yet."

New York Times, September 25, 1983