Fay‹al Karoui never planned to be the music director of a ballet company. But sometimes fate steps in. In 1998, as the new assistant to the conductor of the Orchestra National du Capitole de Toulouse, Mr. Karoui, then 27, was asked to conduct a ballet. "It was The Sleeping Beauty, and I loved it," he says. By the time he conducted Slaughter on Tenth Avenue in Toulouse and Le Tombeau de Couperin for a gala of the Paris Opera Ballet school, he knew he had an affinity for the ballet.

"When I conduct, I like to visualize how the music moves," he explains. "Some conductors prefer to work with the voice. But for me, it's much more natural to work with dancers."

Last year, the young conductor had the opportunity to demonstrate his understanding of ballet. Peter Martins, NYCB Ballet Master in Chief, invited Mr. Karoui — then the music director of the Orchestre de Pau, Pays de B_arn in southwest France — to conduct a performance of Swan Lake. Though Mr. Karoui didn't have an opportunity to rehearse the orchestra — "The first time I met the musicians, I was in my tuxedo in the pit," he recalls with a grin — the performance went well, and Mr. Martins invited him to become a candidate for Music Director, a position that would open when Andrea Quinn returned to England at the end of the 2006 spring season after five years with the Company. During the winter, spring, and Saratoga seasons, the young Paris-born conductor with chestnut hair and elegant hands became a familiar figure in the orchestra pit, leading such diverse ballets as Ballo della Regina, Fearful Symmetries, Symphony in C, and Firebird. In July, he was offered the job, and on December 1, Mr. Karoui began his tenure.

"It's a big jump," he says. "I still have an orchestra in France. And my family is in France. But this is a fantastic company with a fantastic repertory and a music level that is very high. I didn't have any hesitation."

Says Mr. Martins, "Fayçal won us over with his enthusiasm, youthful energy, and, above all, incredible talent."

Though he originally studied to be a pianist, Mr. Karoui, who was awarded First Prize in Conducting at the Conservatoire de Paris in 1997, found conducting came more naturally to him. "The orchestra is the most fantastic instrument in the world," he says. He particularly enjoys the collaborative qualities inherent in the job. "Every day is different," he says. "The members of the orchestra all have different moods, and I love the combination of human emotions. My natural inclination is not to spend hours and hours alone in my practice room, though of course I work on the score alone."

The social aspects of conducting he relishes are magnified in his job as Music Director, where his tasks include overseeing rehearsals, preparing scores for new ballets, collaborating with choreographers, and finding ways to keep the music soaring and the orchestra happy.

Mr. Karoui is off to a swift start. He conducted George Balanchine's The Nutcracker in December and the all-Stravinsky programs in January. And he spends time with the dancers, watching Company class in the morning whenever he can. "I love the way dancers work," he says. "They rehearse in the morning, they rehearse in the afternoon, they perform in the evening, and they never complain. I love their spirit."

As a conductor with such orchestras as the Orchestre de Paris, Orchestre national de Lille, and the Monte Carlo Philharmonic, his repertory has ranged from classical and Romantic symphonic works by Bach, Beethoven, and Mozart, to new works by living composers, which he particularly enjoys. But the music of ballet holds a place in his heart. "If we didn't have ballet music, there would be no Stravinsky, no Rite of Spring, no Petroushka," he says. "So many of the most beautiful pieces of music are for the ballet."

Terry Trucco writes frequently about dance, design, and travel.