William Christie, who will be in town this weekend, may soon be considered the finest conductor of his generation.

He doesn't lead a "Big Five" symphony orchestra, nor has he made a much-talked-about debut with the Berlin Philharmonic. But like the very best conductors, Christie has a knack for making his way seem like the only one possible. He's the star of everything he conducts, with a distinctive style, yet he remains true to each composer's voice.

Buffalo-born and Yale-educated, Christie conducts and plays harpsichord in a French vocal and instrumental troupe called Les Arts Florissants. He trained every member of the group, and it is peerless at what it does, performing exquisite baroque operas and choral works with fine attention to detail and great emotional and psychological depth.

The core repertoire of a typical symphony orchestra conductor today starts with Bach and runs, with gaps, through the mid-20th century, roughly 250 years of music.

Christie is just as broad and just as multination-al, except it's an earlier 250-year swath of history. He's involved with pre-romantic music, stretching from the late-16th-century Italian madrigals of Carlo Gesualdo to Beethoven's "Missa Solemnis," written in the early 1800s--2 1/2 extraordinary centuries.

Christie and Les Arts Florissants make a rare visit to the Washington area on Saturday, when they perform Henry Purcell's small opera "King Arthur," semi-staged by director Ana Yepes, at George Mason University's Center for the Arts in Fairfax.

At Yale in the late '60s, Christie studied with the legendary harpsichordist and scholar Ralph Kirkpatrick. "He was brilliant but irascible--he'd teach German repertoire class in German, and French repertoire in French, and expect his poor students to follow him," Christie says. "He'd want to destroy you and build you up in his own image."

Kirkpatrick's research methods were often unorthodox but usually insightful. While researching composer Domenico Scarlatti (1685-1757), who worked in Spain, he checked the Madrid phone book for any living descendants. Amazingly, he tracked down several related Scarlattis, and they led him to undocumented manuscripts.

Christie had a bumpy relationship with his teacher. "He had some very perceptive things to say about language and music," Christie says. "He'd put texts to Couperin harpsichord pieces. He'd add syllables--even nonsense syllables--to the music to figure out what the syntactic order was all about, in terms of stressed endings in a phrase and non-stressed syllables and elongated syllables. His results were incredible, and he knew that language--syntax, rhetoric and linguistics--is the starting point for good musicmaking. Coming from a harpsichordist back then, that was pretty revolutionary. I learned a lot from him. Funny thing is, he didn't apply much of what was in his brain to his own playing style."

Kirkpatrick later disavowed Christie, though by that point his lessons had been absorbed. Christie went on to teach music history at Dartmouth College for a few years, but his contract wasn't renewed. So in the early '70s, he found himself "a feckless harpsichord player, wandering around Europe, tagging along with a bunch of early- and new-music types, all looking for work."

He settled in Paris, where he and his friends performed both old and new music. Playing piano, organ or harpsichord, he'd mix pieces by such unconventional modernists as Giacinto Scelsi or Morton Feldman with music by obscure baroque composers. "We could seek any interpretative solution that felt right--there were no conventions to observe," he says. "Sometimes it worked, often it was gimmicky, but in the end it convinced me that what I really loved was the ancient stuff, baroque music."

Free afternoons were spent paging through forgotten scores in the French National Library, soaking up music from the Sun Court of Louis XIV--operas that hadn't been heard in centuries. "I was trying to find music that was French, and music that was right for a small number of performers, since that was all we had, and, above all, music that seemed young--youthful," Christie remembers.

For a few years, he found steady employment playing in Rene Jacobs's Concerto Vocale ensemble. Then in 1979, his life's work began on a grand scale: He formed Les Arts Florissants (named after an opera by 17th-century composer Marc-Antoine Charpentier), a flexible pool of about 50 superb singers and instrumentalists, all trained in the rhythmically taut, lyrically sensual Christie style. Their success was immediate, the reviews rapturous.

After that, life seemed charmed. In 1982 he was appointed professor at the Paris Conservatoire, the first American, directing the early-music program. He has proved to be a remarkable nurturer of vocal talent, and there's hardly an early-music singer of merit who hasn't been affected by Christie's language-sensitive interpretations.

By now the French have clasped him to their bosom, awarding him the Legion of Honor in 1993. (Curiously enough, the two top conductors in Paris at the moment, Christie and James Conlon, who leads the Paris Opera, are Americans.)

"The French have a faculty to talk about their past in rather grand ways without being clear on precise terms--30 years ago, French musicians could talk your ear off about how great Jean-Baptiste Lully was, but I don't think any of them really knew anything about his music. They'd hadn't heard much of it," Christie says.

"It's safe to say that if the French hadn't had help from foreigners sorting through forgotten repertoire and bringing it to life today, we wouldn't have these riches available. The French once seemed to have an inferiority complex about their own music, preferring Italian opera and German symphonies."

Of course, most of the top conductors today seem to prefer Italian opera and German symphonies, too, which is why Christie is so intriguing: He's on tour with a 400-year-old English piece, "King Arthur." The libretto is by John Dryden and, following the original form, Saturday's performance will combine singing with spoken theater and dance.

"My first allegiance is to the stage," Christie says. "I love musical theater, and that's the aspect of baroque art that I love--the exuberant, demonstrative, theatrical aspect. And it helps that I'm a ham."

Christie will conduct Les Arts Florissants in "King Arthur" Saturday at 8 p.m. at George Mason University's Center for the Arts. Tickets are available at the concert hall box office, through ProTix (703-218-6500) or through the Washington Performing Arts Society at 202-785-9727 or www.wpas.org.

WILLIAM CHRISTIE RECORDINGS

William Christie, as solo harpsichordist or conducting Les Arts Florissants, has made more than 50 recordings on the Harmonia Mundi and Erato labels. French music is a specialty, but the ensemble's Handel and Monteverdi are also well worth hearing. Many of the group's discs are outstanding; here is a starter list.

OPERAS

Purcell: "King Arthur" (2 CDs; Erato 4509-98535-2)

Rameau: "Les Indes Galantes" (3 CDs; HMC 901-1367-9) and "Castor et Pollux" (3 CDs; HMC 901435-7)

Mozart: "Die Entfuhrung aus dem Serail" (2 CDs; Erato 3984-25490-2)

Charpentier: "Medee" (3 CDs; Erato 4509-96558-2)

Charpentier: "Acteon" (1 CD; HMA 901095)

SOLO HARPSICHORD

Royer: Pieces de Clavecin (1 CD; HMA 1901037)

Rameau: Pieces de Clavecin (2 CDs; HMA 1901120-21)

CAPTION: Staid? Never! "Exuberant, demonstrative, theatrical" is how William Christie views baroque music.

CAPTION: William Christie and Les Arts Florissants will perform a semi-staged version of Henry Purcell's "King Arthur" on Saturday at George Mason University.