J. Reilly Lewis’s life has not gone according to plan. After joining the Junior Boys’ Choir at Washington National Cathedral and taking up piano at age 8, he attended Oberlin College with the intent of becoming a doctor. But one squeamish day in biology class ended his medical ambitions for good. Lewis wound up at Juilliard only after he missed the application deadline for another school. That he has been the music director of the Cathedral Choral Society for more than 25 years is, you could say, the work of a higher power. On Sunday, Lewis will lead a singalong of “Carmina Burana” at the cathedral. The internationally renowned Bach specialist discusses divine intervention, the frog that changed his life and why “Carmina Burana” can make anybody blush.

“I’ve lived here virtually all my life. We moved out to Washington from California when I was 10 months old, and I started out at the cathedral when I was 8 years old as a member of the choir. I rebelled all the time I was in choir. I got into all kinds of trouble.

“At Oberlin, I started out pre-med. I loved music so much I didn’t want to make it a job. My junior year, I had to kill a frog in biology. I couldn’t do it. I put him in my pocket and carried him out to the creek, where I had this cathartic moment: ‘Who am I kidding?’ That frog changed my life.

“I wanted to go to Union Theological [Seminary]. I wanted to pursue a career, as I have, as a church musician. But I was too late to apply. I thought I was a pretty strong case for making an exception, because I thought I was exceptional! I played the organ as my audition for admission, and he said, ‘Thank you very much. I hope you apply on time next year.’

J. Reilly Lewis, music director of the Cathedral Choral Society for more than 25 years, wanted to be a doctor until one squeamish day in biology class. (Steve Sullivan)

“At that time that Union was right across the street from Juilliard. I walked right out the door at Union and into the door at Juilliard. It was divinely ordained. I believe it was something that was beyond my own control or power of foreseeing.

“Being at the cathedral, there’s such a wow factor there. What speaks to me, more than the dogma or the doctrine, is great music lifting that word into some other space.

“To do ‘Carmina Burana’ in any church, let alone the Washington National Cathedral, some people would see that as absolute blasphemy. . . . It’s just a real romp. It’s all body, these rebellious monks and their lascivious writings and thoughts. It’s so rowdy and bawdy and visceral and kinetic. It’d make anybody blush.

“I feel like I’m still learning. The older I get, the more I have to learn. That’s the wonderful thing about art, music, literature: It really is transcendent. Even with works that you’ve done many, many times, going back to them, going back to the great classics of any field, is always a renewing experience. You learn something new, not just about the piece but about yourself.

“Whenever I go into the cathedral, I’m filled with awe, wonder and humility. Every time I cross the river, I look to my right on Roosevelt Bridge to the cathedral up on the hill and I smile. I think I’m the luckiest guy in the world.”

The “Carmina Burana” singalong is Sunday at 7.30 p.m. at Washington National Cathedral, 3101 Wisconsin Ave. NW. Tickets are $10. Call 202-537-6200 or visit nationalcathedral.org