NEXT: `MISS SAIGON'. Boublil and Sch"onberg: A French writing partnership dubbed a Rodgers and Hammerstein for the '90s. INTERVIEW: THE MEN BEHIND `LES MIZ'

THE door of the hotel suite opens. Alain Boublil, a dark-haired, boyishly handsome Frenchman standing in stocking feet, smiles with welcoming informality. He quickly slips into easy conversation, curling up on the sofa, feet tucked underneath. Partner Claude-Michel Sch"onberg soon walks in to join the interview, exuding a similar air of casual affability. At first glance, it's hard to believe that these two easygoing, unpretentious men are responsible for creating ``Les Mis'erables,'' the musical that has made stage history.

Following its premi`ere in London just over three years ago, ``Les Miz,'' as it has affectionately been called, has spawned 13 productions around the globe, with a dozen more in the offing. Indeed, the show has reached a staggering 72 cities worldwide, from Washington to Warsaw, and grossed, by the end of last year, somewhere in the region of $450 million.

Cameron Mackintosh, the British producer who first backed Boublil and Sch"onberg, has described the impact of ``Les Miz'' as ``mind-boggling.'' Speaking with him later, it became clear that even this producer, with a string of hits including ``Cats'' and ``Phantom of the Opera,'' is stunned by the show's success.

``Unless something terrible happens to it,'' said Mackintosh, ``I would think that within the next 18 months `Les Mis'erables'' is destined to become the biggest box office success - of anything, really - in history.''

Trying to catch lyricist Boublil and composer Sch"onberg for an interview is no mean task. The pair are constantly on the move, overseeing each production of ``Les Miz.'' ``We have a hand on every note of our work,'' says Boublil in near-perfect English, ``which means that no one is telling us stories or cheating us somewhere. ... It takes a lot of time.''

What free moments they do have are spent putting the finishing touches on their newest work, ``Miss Saigon,'' which goes into rehearsal shortly and is scheduled to premi`ere in the West End here next fall. With Mackintosh again as the producer, plus nearly all of the same ``Les Miz'' creative team, it could well be yet another megamusical.

``Miss Saigon'' is an adaptation of the Puccini opera ``Madama Butterfly,'' the heart-wrenching story of a young Japanese girl who falls in love with an American sailor and is abandoned - though she devotedly waits for him - only to be asked to give up their love-child when he returns with an American wife.

In ``Miss Saigon'' the story is updated some 100 years to the 1970s, beginning with the close of the Vietnam War. The action takes place largely in Thailand, with the protagonists a Vietnamese girl and her United States soldier lover.

But the show will not be simply a rehash of Puccini. For inspiration, Boublil and Sch"onberg have gone back to one of the forgotten sources of the opera: ``Madame Chrysanthemum,'' an intriguing novel of subtle intricacy by French writer Pierre Loti. So while it can be said that the broad outline of this totally sung musical will be the same as the opera, its progenitors say ``Miss Saigon'' is really an extremely loose adaptation, combining the original spirit of the story with a wholly contemporary mood.

``In the end, it will probably be to `Madama Butterfly' - we hope! - what `West Side Story' was to `Romeo and Juliet,''' says Boublil.

The concept is particularly exciting to its creators for a number of reasons, not least that it's so different from anything they have done in the past. In addition to ``Les Miz,'' their only other musical was ``The French Revolution,'' written in 1973. ``This is definitely not `Les Mis'erables II,''' Boublil emphasizes. ``And so there is a sense of danger in this for us, something new for us to prove.''

``We don't have a great novel behind us to rest on,'' adds Sch"onberg, referring to Victor Hugo's masterpiece in the case of ``Les Miz.'' ``We are working without a safety net.''

``And that's a wonderful, very exciting feeling,'' Boublil observes.

Producer Mackintosh, renowned for his judgment about musicals, is also drawn to the project, in part, because of the risk involved. ``The moment I heard the score,'' he recalls, ``I thought it was very, very special and, in a way, appealingly dangerous. It's a contemporary musical. Most musicals aren't contemporary; I can only think of `West Side Story' and `A Chorus Line.' But I also thought that the whole idea behind it was very moving.''

THE rise of Boublil and Sch"onberg is all the more remarkable when one considers their past. Surprisingly, France does not have a musical theater tradition. Before the two men wrote ``The French Revolution,'' an idea they got after hearing Andrew Lloyd Webber and Tim Rice's ``Jesus Christ Superstar,'' they were both working separately in the popular music industry. Following two years of labor over the project - something their French colleagues considered utterly mad - they were stunned by its instant success.

It took another five years before the pair came up with the notion of putting Victor Hugo's classic to music; and Sch"onberg recalls that, until 1986, he would wake up every night wondering whether he could cope with yet another year at subsistence level. ``Writing songs and working on musicals is so irregular,'' he notes.

Now this team is being hailed by Mackintosh and others as a ``latter-day Rodgers and Hammerstein'' - two men whom Boublil and Sch"onberg had, in fact, never even heard of until after ``Les Miz'' was completed.

``The more I work with them,'' Mackintosh observes, ``the more I realize that they are an extraordinary talent. And I think they are destined to be considered one of the greatest writing partnerships of the 20th century.''

The reasons for the comparison go deeper than simply that, like Rogers and Hammerstein, Boublil and Sch"onberg, too, are writing as a composer-lyricist team. As with their great predecessors, the two Frenchmen also believe emphatically in basing their work on a serious premise and making the show's book as strong as possible - a point many musical writers these days seem to ignore.

``To start writing lyrics or music, for me,'' says Sch"onberg, ``the motivation must be the best book that you have ever had. If the book is not perfect, you have no motivation to start two hours of music and two hours of lyrics, because it's such a difficult process. It takes three or four years between the moment you start to think about a project and when it is finished. So you must have terrific motivation. And for that, you simply must have a wonderful book.''

Boublil recently read Rodgers and Hammerstein's ``South Pacific'' for the first time, having never seen the show performed. ``And when I read it,'' he says, ``I realized that these two people were thinking the same way that we are, not only from the point of view of a perfect collaboration - words mean the same thing to Claude-Michel and myself - but that they were aiming for the same goal. ... It used to be said that there is no opera without love, honor, and death. `Miss Saigon' is even more like that than anything we have done before. So we are going back, in fact, to the essential roots of the Italian opera, as well as musical theater.''

Although Boublil and Sch"onberg have been creative partners now for over 20 years, it's only in the last three that they feel they have finally found the right track. And it is this discovery, far beyond the considerable monetary gains, that they both see as so rewarding about the work they are doing. ``It's like I have suddenly found the main road which I have always been looking for,'' says Boublil. ``I now have the impression that I have a profession: I am a musical-theater writer. And I am very proud of that.''

But for Sch"onberg, the biggest thrill is even more personal. ``Before, when I was listening or watching `West Side Story,''' he muses, ``I wanted to be Leonard Bernstein. And after watching `Evita,' I wanted to be Andrew Lloyd Webber. Now, sometimes, listening to `Les Mis'erables' or listening to the `Miss Saigon' demo, you know, I just want to be myself.''