Eschenbach's is the European answer. Earlier in his creative life, the 47-year-old Dalbavie loved scattering instruments throughout any given hall, surround-sound-style, and many of those pieces - such as The Dream of the Unified Space - were for the Cleveland, Chicago and Minnesota orchestras. In America, the typical onstage orchestra can seem like an exception for Dalbavie.

Such dreams - inspired by wall-to-ceiling frescos of the Italian Renaissance - have made him one of the most-played living French composers in the United States. That spatial quality is still there, just confined to the stage now. "You can see the melody traveling the orchestra, coming in from the back and going to the front," he said the other day. "That comes from the space pieces . . . but I've explored what I wanted to explore."

Now, his pieces are like Rube Goldberg apparatuses, with diverse but simple musical components set in motion. Such music easily fits into typical symphonic program slots, which perhaps is one reason why his commissions involve major artists and multiple orchestras. La Source d'un regard was prompted by Amsterdam's Royal Concertgebouw Orchestra, but co-commissioned by the Philadelphia Orchestra and Bamberg Symphony.

The piece commemorates the centennial of venerated French composer Olivier Messiaen. But since Dalbavie is of the first generation of French composers not taught by Messiaen (who died in 1992), he took an approach similar to Jennifer Higdon's in Mr. Carter's Notes, a tribute to the elder (and unlike-minded) Elliott Carter: He lifted chords from one of Messiaen's best-known pieces (Vingt Regard sur L'Enfant Jesus) and ran with them - his own way.

"I try to explore a new kind of polyphony, not based on counterpoint, but a little like what Charles Ives tried to do, superimposing different kinds of music," Dalbavie says. "You can isolate different musics that come, disappear, and come back again, each time transformed and interacting with what's happening at the same time."

Charles Ives? For all its Gallic outer garments, Dalbavie's music has an American manner, also suggesting American minimalists. Because he's always asked about the Debussy factor in his music, Dalbavie hasn't really mentioned Ives until now. Also, his use of repetition, particularly evident recently, could have come only in the hypnotic wake of Steve Reich's Music for 18 Instruments - one reason that U.S. orchestras seem to take to him instinctually.

But unlike some minimalists, Dalbavie is not one to establish a compositional procedure and let it pursue its ultimate conclusion. "When you start repetition and transformation, it has a strong logic," he says. "I introduce contradiction in the process."

That's what happens inside his pieces. Outside, Dalbavie is enjoying critical mass. In the 1990s, he was characterized as a mild-mannered family man who lived in a 15th-century farmhouse in rural France, visiting the Cleveland Orchestra while composer in residence in 1999, and later, Orchestre de Paris, where he was composer in residence, and chosen by Eschenbach.

It turned into a high-impact relationship for Dalbavie: "I've heard a lot of concerts [by Eschenbach] that impressed me, even in pieces of music I really don't like. The performance [of Shostakovich's Symphony No. 5] was so fantastic I needed two or three days to recover from the completely mystic and mysterious feeling."

So far this year, he's had three high-profile premieres - the vocal-orchestral work Sonnets in Lyon, France; his Trio No. 1 for Violin, Cello and Piano on Sunday at Carnegie Hall; and now the U.S. premiere of La Source in Philadelphia - plus his most mainstream recording yet, Concerto pour flute on EMI by star flutist Emmanuel Pahud.

"When I was young, I wrote one piece every two years. I didn't want to write a lot of music. I wanted to think a lot on each piece," he says. "When I was 35, around 1995, it was a moment in my life when I wanted to . . . take on a lot of artistic experiments. I became hungry."

That got him into some fairly crazy situations. In an Orchestre de Paris commission, he wrote a companion piece to Mahler's Chinese-influenced Das Lied von der Erde for Asian instruments. Titled Double Jeux, the music was exotic, but the experience maddening, particularly with multiple translators necessary for the ethnic mix of musicians in rehearsals.

Earlier this year, Dalbavie found himself with simultaneous deadlines for Sonnets and Piano Trio - two distinctly different pieces that lent themselves to being written at the same time. "What I couldn't do in the Sonnets, I did in the trio," he says. "I'd work three days on Sonnets, three days on Trio."

Though the trio's premiere was well-reviewed this week, the rhapsodic, ecstatic Sonnets appears to be the bigger breakthrough. Dalbavie long wanted to musicalize the 16th-century erotic sonnets of Louise Labe, but waited for years for the right soprano. Finally, he instead chose popular countertenor Philippe Jaroussky, who seems headed for rock-star status in Europe, and whose vocal androgyny suits the poems of a woman whose life defied gender stereotypes. Particularly striking are the music's perfectly graceful vocal lines, seemingly influenced by liturgical chant, with plenty of room to accommodate a character. Dalbavie would seem to be primed for opera.

The composer is aghast, as if in mentioning that, you're reading his mind: "You are not totally wrong," he says. "I have a project [in opera], but it's not totally set up yet. When I wrote Sonnets, I thought a lot about the way to develop a vocal line. . . . Most people who go to opera want to hear singers. Some might care about the story. But they're really there for the song. Opera is really the temple of the voice."

With that major artistic door opened, we need only wait for him to enter.