William David Cooper is a former starting high school quarterback from Michigan who retains his passion for the sport and, in particular, the Kansas City Chiefs. In that context, in a phone conversation last week about his arrival in New England, he's a bit nervous given that KC had just thwacked the Patriots in solid fashion. He hopes his allegiance to the Chiefs won't be held against him.

No worries.

Y'see, long before the nights when he threaded tight spirals between the seams of opposing defenses, Cooper was a 5-year-old taking piano lessons and starting to appreciate the nuances and sublimity of classical music. It's been an enduring passion and is now a stellar career. Last November, for example, Cooper — "Just Will, please" — came onboard at St. James Episcopal Church in New London as organist and choir director.

"St. James is a wonderful community and a great group of people," says Cooper, now 31. "The choir is dedicated and fantastic and a real joy to work with. The building is beautiful, and the organ is so much fun to play. And Father Mathews is the new rector; we're very blessed to have been energized by his passion, so I'm very excited about the music ministry going forward."

Rev. Ranjit K. Mathews came to St. James four months ago and was at once impressed with Cooper.

"He's a wonderful man, and he has wonderful musical and artistic gifts and certainly an amazing personality," Mathews says. "What he offers in terms of the integration of music into our worship are a gift to us."

But his work at St. James is just a small part of Cooper's artistic pallete. He lives in Boston and commutes to New London for Thursday rehearsals and Sunday services, as he's also insanely busy as an internationally renowned composer of opera and orchestral, chamber and choral music. His resume is filled with dazzling accolades: studied at Juilliard, a PhD from the University of California at Davis; works-in-progress for the Aspen Music Festival (chamber piece), the Scharoun Ensemble in Berlin (octet) and a grand opera called Hagar and Ishmael.

He's also received a Cal-Davis Provost's Fellowship, a Charles Ives Scholarship from the American Academy of Arts and Letters, three Morton Gould Young Composers awards, and numerous other grants, fellowships and commissions. Cooper's music has been performed by such prestigious artists as Grammy-winning violinist Augustin Hadelich, soprano Tony Arnold, the JACK Quartet, the Lysander Trio, Antico Moderno, and the Empyrean Ensemble.

Is it possible Cooper had this planned all along, even during those earliest piano lessons?

"I knew I loved music and the challenge of imitating Mozart and Beethoven, but I wasn't doing a lot of self-reflection," he says. "I didn't think seriously about the state of contemporary classical music. But I remember I did think it would be a nice career."

In high school — presumably while not wearing shoulder pads — Cooper started to learn about composers working in the 20th and 21st century and was fascinated. He also began to write his own classical structures.

"I was encouraged to enter a contest in Kalamazoo and, much to my surprise, they selected my piece," Cooper remembers. "I got to hear a 70-piece symphony play it, and it was incredible. And that's when I decided I would be a composer." He laughs. "I didn't understand what the process would be or how incredibly competitive and difficult it's been. But I don't regret it one bit."

Cooper attended a public high school through his junior year, and he was a little embarrassed by his love of classical music since all of his friends and contemporaries listened to contemporary rock, rap or country.

"Someone would ask me who my favorite bands were, and I could throw out a few," he says. "The thing was, I was listening to contemporary music, too, just in a classical sense: Olivier Messiaen, Witold Lutosławski, Sergei Rachmaninov ..."

For his senior year, Cooper transferred to a boarding school and found more like-minded students and experienced a sense of "freedom to be myself. That was important."

Throughout his schooling and even today, Cooper was and is exposed to the same modern sounds and techniques that influence most contemporary classical composers to one degree or another — world music, minimalism, ambient/electronic, even film soundtracks.

"I do have a lot of different influences, and it's impossible today to not be exposed to a wide variety of music," Cooper says. "I try to embrace any sound I hear that I like, and I think about how to employ it in my music. Going back to the Renaissance, I'd say most of my musical influence is ground in the Western classical tradition. But I try to draw from it all, and I'm always trying to expand my repertoire of sounds and aesthetics."

Cooper says a priority is that his music should have a lyrical quality, even when he's writing choral or chamber music. "I always imagine the instruments are singing," he says. "The thing I love most is composing opera and for voice in general. I find it very inspiring to write based on a story or a text; it makes the process easier for me."

A long-term and favorite project is Ishmael and Hagar, a two-act opera-in-progress based on the biblical story.

"I've been working on it for six years and it's almost finished," Cooper says, "and the combination of the text and the music has a synergy. This goes back to the time of Wagner, who felt that music and all the art forms were most powerful when they were combined in some fashion."

The reality for modern classical composers is that there's almost always a "day job" component.

"A lot of us don't have the luxury to compose exactly what we want or are inspired to compose at a certain time," he says. "I generally compose on commissions — which I enjoy for a lot of reasons but also because it helps to have a deadline. I can obsess on something for several years" — he laughs — "as with Ishmael and Hagar."

The gig at St. James offers a welcome creative challenge. He loves the Thursday and Sunday focus and energy working with the choir at the church, and also the freedom to focus on his own the rest of the week.

"I find that composing and directing music at a church can go hand-in-hand pretty well," Cooper says. "Bach is probably the greatest example of a church musician/composer. I really enjoy composing hymns, for example, for the church, and that's a great example of the work overlapping. We have a great poet in the choir, Anne Bingham, and we've been collaborating on anthems. She recently sent me a poem on Epiphany, and the plan is for the choir to perform it when we're done. Just to be able to play and work with this wondeful choir has been a huge blessing."

Cooper's energy, talent and presence has been a delight, says choir member Katherin Brightly.

"As a group, we're quite passionate about English and American music written for the Anglican/Episcopal church, and Will has an excellent background in that realm. He's also stretched our musical tastes, and he brings a broad enjoyment of music to every rehearsal. His musical skills amaze us. When he plays organ, all kinds of creative things are going on — dissonant chords emerge when evil is being described; trills or flowery touches behind light phrases — and it's such fun to sing with all that richness happening," she says.

It's also fun that Cooper's girlfriend, Eun Young Lee — also a PhD-level composer —  has joined the St. James choir as a soprano.

"She's just as wonderful, musically and personality-wise, as Will," says Brightly. "They feel like family to the entire choir."

As for long-ago football glory, Cooper still has his moments. "I really enjoyed playing football but had no pretensions I'd play in college or beyond," Cooper says. "I do have weird dreams where football strategy and composing are intertwined in a strange way. I can't figure out how that works or what it means, but I do sort of find it comforting."