When a new production of a performing arts masterpiece truly revives its subject, it is able to remind us, sometimes in fresh and different ways, why the work came to be called a masterpiece in the first place.

"My Fair Lady," first presented 45 years ago on Broadway, is one such masterpiece. Created by composer Frederick Loewe and librettist/lyricist Alan Jay Lerner from George Bernard Shaw's 1914 play "Pygmalion," it is one of the great works of American musical theater. Its songs and dance not only reflect but enhance and enrich Shaw's original story of a Cockney flower girl transformed into a cultured young woman by a self-centered professor of phonetics who teaches her how to talk and act like a lady.

With Rex Harrison as Henry Higgins, the professor, and a very young Julie Andrews as Eliza Doolittle, the flower girl, the first production in 1956 became a legendary success, one of the great flowerings of the golden age of Broadway musicals in the 1950s.

First impressions

Any production attempting to revivify this "Lady" has to go up against the indelible impression that this first superb staging (by Moss Hart) created. Subsequent London and Broadway revivals, some with Harrison reprising his role, stuck closely to the original in design and performance; and the 1964 movie, with Audrey Hepburn as Eliza, has further reinforced the performance through its many showings on television and on video screens. Efforts to radically reinvent the somewhat frayed material -- such as the 1993 production directed by Howard Davies and starring Richard Chamberlain, in which the Ascot race scene was designed as if painted by the surrealist Rene Magritte -- were, at best, "interesting."

This year, however, Trevor Nunn, the innovative director of "Cats" and "Les Miserables," has brought "My Fair Lady" back to triumphant life in a production at the Royal National Theater in London that, while it never erases the memory of the original, reasserts the supremacy of the musical in new and stimulating ways.

In his tenure as artistic director of the National, Nunn has made a practice of reviving classic musicals. "Oklahoma!" was the first such staging in 1998, and, beginning this August, Nunn will revisit Rodgers and Hammerstein's "South Pacific" (with Lauren Kennedy, now in "The Last Five Years" at Northlight Theater, set to appear in Mary Martin's role as Nurse Nellie Forbush).

Critics have complained that these shows are crassly planned as box-office hits for future commercial transfers; and, in truth, both "Oklahoma!", due next season on Broadway, and "My Fair Lady," which transfers to Drury Lane theater in London July 21 after its run at the National ends this month, have been taken up by the very commercial producer Cameron Mackintosh.

But when the results are as sumptuous and stunning, and as revealing, as those in Nunn's "Oklahoma!" and "My Fair Lady," these arguments are lost in the triumph of the revival. If "Death of a Salesman" is a classic of American theater, so is "My Fair Lady," and it is equally deserving of an inspired revival.

"Lady" is not quite the breakthrough rediscovery that Nunn achieved in "Oklahoma!" In tone and design, it is still anchored in the drawing rooms of the Edwardian era. But Nunn has imaginatively placed the musical's story in its social and historical context. Newspaper signs in street scenes proclaim the death of King Edward VII in 1910, leading to an all-black (for mourning) costume design for the socialites at the Ascot races. And when Eliza tells off her young suitor Freddy Eynsford-Hill by urging him to "Show Me!" she ends her plea by joining a group of feminists parading for women's right to vote.

Anthony Ward's production design cleverly uses moving sidewalks to glide seamlessly and swiftly from one scene to the next; and Matthew Bourtne's dances, while respecting the original verve of Hanya Holm's choreography, build new bits on the originals. The exuberant "With a Little Bit of Luck," for example, spills out of a pub and into the streets of the Covent Garden area with a "Stomp!"-like percussion chorus of pots, pans and garbage cans.

But the chief refreshment of this production is in the characterizations and relationships of Eliza and Higgins.

A pleasing combination

Jonathan Pryce, in a performance of great intelligence, is a thoughtful, if sometimes thoughtless, Higgins, less acerbic and more scholarly and gracious than Harrison -- and he actually sings the songs. Martine McCutcheon, a recording and television actress with relatively limited stage experience, does not have Andrews' miraculous vocal range, but she's an attractive and likable actress, a feisty, smart Eliza who is more than a match for Higgins, and she sings with a big, expressive voice.

They're a pleasing combination, and their final scene, staged simply and wittily by Nunn, brings their combative relationship to a joyous conclusion, closer to Shaw's intent than that devised for Harrison and Andrews in the 1956 production.

Dennis Waterman turns the role of Eliza's roistering father into a meaner, tougher character than Stanley Holloway's beloved original interpretation; you believe him when he tells Higgins that one way to handle Eliza is to give her a few good knocks in the head. But Nicholas Le Prevost, as Higgins' gentlemanly associate Col. Pickering, and Mark Umbers' moonstruck Freddy add ably to the glossy refurbishment of the show.

It seems inevitable that this "Lady" will make its way to Broadway, with, one hopes, Pryce still in top form. That may take a couple of years, however.

For the moment, this is a "My Fair Lady" that is fair indeed, one that pays tribute to the past while setting its own distinct course to glory.