French composer Henri Dutilleux lived for decades in a small studio apartment on Île Saint-Louis in Paris, France. When time allowed, a promising young conductor, Ludovic Morlot, who is now Seattle Symphony's music director, would call up the old composer in the afternoon in hopes of arranging a visit.

"Maître, I'm in town for a few days and I would love to see you!" Morlot would say.

"Oh, I'm too tired, Ludo, but why don't you drop by for a few minutes? If you're here, I want to see you. But I can only do a few moments," Dutilleux would reply.

"Of course," Morlot would say. "But I'd be happy to ask you a few things about a piece I'm working on..."

A few hours later, the two would still be drinking martinis or glasses of porto and talking about music, literature (especially the poems of Baudelaire), visual art, and life. At this point, Dutilleux was in his late 80s and early 90s, a living legend of French impressionist music, elegantly dressed in a crisp button-up shirt, jacket and silk scarf, with slicked-back hair—reserved, but passionate once he got going on a topic.

When he was younger, he'd developed relationships with composers such as Roussel, Poulenc, Milhaud, Stravinsky, and Prokofiev, all of whom spent time in Paris before the war, and he'd pass down their lessons and stories to Morlot, an eager student and a fellow steward of the art. Eventually, Morlot would pass along the stuff he learned from Dutilleux to his younger colleagues, and thus continue on an intellectual and artistic tradition that reaches back to Ravel and Debussy, one that's more concerned with the many colors you can create with symphonic music rather than the rigid structures that often define it.

Dutilleux's apartment hadn't been redecorated since he initially moved into it. You could travel back 50 years just walking into the place. Antique furniture was scattered all around, pictures and paintings lined the walls, bookshelves were stuffed with poetry and novels. And, of course, a full-size piano sat in the corner of the room. On the piano's music stand, Dutilleux would have score sheets of whatever he happened to be working on at the time—and if you walked in at any given moment, you could catch him making revisions to the song cycle he just wrote.

He'd sit at the piano and play with it as he spoke with Morlot. "I'm wondering about this chord—what do you think?" he'd say. The chord would lead to a conversation about a feeling or a mood or a poem or a painting, which would lead to another conversation, and so on.

Morlot would ask Dutilleux questions to gain insight about composition choices, which would help him to conduct Dutilleux's work better. How many voices should go in the children's choir—or maybe he could just use one? What kind of cymbal should he hit here? Should there be lots of vibrato on this note or no vibrato?

In one of Dutilleux's violin concertos, there's a moment before the last movement starts where the entire orchestra is asked to retune onstage, but the retune is scored in a very specific way. Morlot asked why Dutilleux would make that choice, and his mentor said that the retuning embodied his struggle with writing the piece. Dutilleux got stuck while he was creating it—he didn't know how to finish. When he thought to have the orchestra retune seemingly out of nowhere, it felt like buying a new notepad. Fresh ideas poured in, allowing him to complete the piece.

Dutilleux always had a story he wanted to tell in his music. He had no intention of making abstract music written only to satisfy a structure. (Lots of his pieces were written for certain singers, and many are dedicated to his wife, the great pianist Geneviève Joy.) He also took a long time between publications, and he was constantly revising and touching up his work. So if Dutilleux made a weird choice in a composition, there were probably several reasons for that choice—and those reasons are helpful to know for someone like Morlot, a conductor whose task is to breathe life into little black dots on a cold white page.

Dutilleux also instilled within Morlot a sense of seriousness about the music. The hours that go into creating the music and then interpreting that music for performance are what make the work art and not just entertainment. Even if only a handful of people appreciate the little gestures—the difference between plucking a string with a fingernail or a finger, let's say—the endless hours of conversation and revision and thought are worth it. Dutilleux showed Morlot that the general assumption is true: Symphonic music is complex enough to endure lots of intellectual scrutiny and emotional analysis, and it repays your attention with a tremendous sense of fulfillment.

Morlot in some ways repays his mentor by consistently championing and producing his work—which is earning laurels for both of them. This year, Seattle Symphony took home a Grammy for its recording of Dutilleux's violin concerto L'arbre des songes.

In August, Seattle Symphony's music label plans to release a three-disc box set of the symphony's recordings of Dutilleux's work. The release seems to be garnering lots of international press, if the fact that I bumped into a Parisian journalist named Elsé (call me) in the elevator at Benaroya Hall is any indication.

I was en route to Morlot's office to interview him for this article, having just seen him conduct a concert the night before that featured Dutilleux's Timbres, espace, mouvement and Beethoven's Fourth and Prokofiev's Seventh Symphonies.

Before I started asking him about Dutilleux's strange and haunting music, I wanted to know how to pronounce the composer's name.

"What you have to say is Doo-tee-yuh," Morlot said.

Doot-ill-oh, I replied, as if Morlot's mentor was some kind of snack cracker.

"No, no. Doo. Tee. Yuh. Dutilleux," he corrected.

"Doot-ill—"

"Think of the vowels," he said.

After some training, I could look at the letters D-U-T-I-L-L-E-U-X and then say "doo-tee-yuh" in response, but it required a bit of attention and a little direction. I had to ignore ingrained assumptions about the way the letter L works, and I also had to remember the idea that letters are really just symbols that correspond to sounds that different cultures pronounce in different ways.

The kind of attention you have to bring to bear when saying Dutilleux's name for the first time matches the level of attention you need to bring to his music if you want to get a lot out of it. Which—you don't have to. You can just sit there in the audience and feel stuff and enjoy the movie his music injects into your mind, as I did when I heard it at the concert the night before.

When the orchestra played the first note of Dutilleux's composition, I thought of myself in a dark field with a creepy stone tower jutting up from its center. Dutilleux's piece was inspired by Vincent van Gogh's The Starry Night, so that image tracks with the composer's intentions. As the music continued, a friend and I ran around the dark field, ducked behind boulders, investigated the tower, got freaked out by the tower, got cornered by some strange shadow monster in the tower, and then—just as we were about to be consumed by the shadow monster's total darkness—the Beethoven kicked in and dropped us into a sunny meadow. (Thanks, Beethoven!) Suddenly, my friend and I were both a couple of Renaissance lads frolicking in the tall grass, getting in scrapes with troubadours by a crystalline stream. When the Prokofiev started up, we hopped on the backs of horses and galloped toward town. Snow started falling gaily from the clouds, and our meadow transformed into a bustling, midcentury Russian village. Children pushed each other around on toboggans in the square while their parents tried on gold watches in the watchmaker's shop. But the final movement's manic, carnivalesque romp made us think that everyone was secretly about to kill us. Fin.

"This is why I try not to tell people what the music means," Morlot said after I described all that to him. "Because everyone has their own responses, and I love them."

Some symphonic music is more open to personal interpretation than others.

"Beethoven takes you by the collar, by the guts, and says, 'This is what you have to deal with. Your fate.' Bum-bum-bum-BUMMM! Why do you think we call that the 'Fate motif'?" said Morlot, referring to the apocryphal story of Beethoven's secretary claiming the composer described the opening move of his Fifth Symphony as a musical translation of Fate knocking on the listener's door.

I asked if bum-bum-bum-BUMMM translated to "You're gon-na DIE!"

"Yes!" Morlot said, "Or 'This is the END!' It can be anything."

But Dutilleux's music doesn't grab you and drag you around like Beethoven's does. Morlot described Dutilleux's compositions as having an intangible quality, one that doesn't dictate the way you should be thinking but rather suggests a world full of possible thought.

Dutilleux's pieces are incandescent, warm with the intensity of a real torch, but one that's burning within your body. To achieve this effect, Dutilleux combines very unusual notes that create sounds you've never heard before.

To illustrate this point, Morlot sat down at the piano in his office. "The bones of the first movement you heard last night are composed of a tritone, which is known as the devil's interval, which was forbidden in the 17th and 18th centuries because the note is so discordant, they thought it represented evil," he said. I started getting a little excited. I was getting facts! And I was feeling a little like Morlot must have felt in Dutilleux's Parisian apartment. In fact, Dutilleux would mention during his meetings with Morlot little insights like the one he was about to show me—"Ludo, did you happen to notice..."

"The movement starts with the G sharp and then ends with the D," Morlot said. Then he played them both together to create the sound of the devil's interval.

He went on: "But in the second movement, you get this one"—he played a more melancholy sounding chord—"which starts with an F sharp and ends up with the whole orchestra playing the A sharp." That chord he played was much more consonant. "You're comfortable with this, right?" he asked. I was.

"If you play these four notes together"—he played the G sharp, D, F sharp, and A sharp—"then the whole piece can be summarized as that four-note chord," he said. "And look how it feels like suddenly there's this incandescent quality to it..." He pressed the keys a few more times, listening intently to the chord, as if it were telling him a secret. "It's not quite consonant, but it's not quite clashing either. There's a zone of comfort," he said. I said it sounded like sour gold.

Whatever color Dutilleux's chords taste like to you, they serve to establish a complex tone that washes over your sensorium, turning up subtle feelings—stuff you haven't quite sorted out yet.

"You know what this journey is, right?" Morlot said, before playing Beethoven's "You're gon-na DIE" motif followed by a bright chord in C. "Darkness to lightness."

Then he played a bright but sour chord followed by a brooding minor one. "That is somewhat of a journey as well," he said. "But it's much more subtle. You get to decide what that journey is."

Though Dutilleux's journeys may be subtler than someone like Beethoven's, they're by no means less powerful. The piece I heard in April—Timbres, espace, mouvement—transforms Van Gogh's night sky into what feels like four hundred cellos cut through with swirling flutes. The feeling of immensity, impending doom, and squaring up with fate is all there, but so are the stars—bright, incandescent torches blazing out against the blue-black void.

Dutilleux's music allows us to access these vaguely spiritual feelings without being ashamed of them—the ineffable, the intangible, the life in death or the death in life. Just listening to one chord will give you goose bumps, but you won't know why.