Classical music lost a promising pianist when 16-year-old Judy Collins fell in love with a folk song she heard on a Denver radio station.

The year was 1955, and the recording was The Gypsy Rover, also known as The Whistling Gypsy, from the 1954 Alan Ladd movie The Black Knight. Ms. Collins was taking a break from practicing Rachmaninoff’s demanding Piano Concerto No. 2 when the song came over the airwaves. She found it irresistible.

“I just flipped my lid,” said Ms. Collins, now 78, who performs at the Old Whaling Church in Edgartown June 8. Another song that fired her young imagination was Jo Stafford’s version of the ballad Barbara Allen.

“By the time I heard both of these songs, I was a convert,” she said. “I was absolutely in love with this music. I never looked back.”

Judy Collins performs in Edgartown on June 8. — Peter Simon

The hard part was telling her piano teacher, the pioneering conductor Antonia Brico (1902-1989), that she was leaving classical music.

“She wept. I wept,” recalled Ms. Collins, who spoke with the Gazette by phone from her Manhattan home. Ms. Brico, who had studied Bach in the jungle with Alfred Schweitzer and conducted her own orchestra at Carnegie Hall for years during World War II, had imagined a triumphant piano career for her teenaged Denver prodigy.

“She was not Miss Pringle over at the high school. She was a world-class conductor and she was the one I had to go and tell that I was going to sing The Gypsy Rover and The Blue-Tailed Fly instead of playing Rachmaninoff,” said Ms. Collins, laughing. “It was hysterical, in a way.”

Long after Ms. Collins became an international icon of contemporary folksinging, her pellucid voice propelling hits such as Send In the Clowns and Both Sides Now, Ms. Brico remained disappointed in her former student. Even when Ms. Collins produced an Academy Award-nominated documentary about Ms. Brico’s trailblazing career as a female conductor, her early mentor was unimpressed.

“I think she was still mad at me,” Ms. Collins said, in all seriousness. But the 1974 documentary, Antonia: A Portrait of the Woman, did revive Ms. Brico’s conducting career, she added.

And while Ms. Collins happily abandoned her classical studies to pick up the guitar, she continues to play piano and write all her songs at the keyboard.

“I’m a pianist at heart, and always will be,” she said. However, recent finger surgery means she will not be performing on either piano or guitar during the Old Whaling Church concert, Ms. Collins added.

“My great accompanist and musical director, Russell Walden, will be playing piano,” she said. “It will be a first for Martha’s Vineyard: Judy singing and Russell playing.”

Ms. Collins, who owns her own record company, has two new CDs out in 2017: the recently-released A Love Letter to Stephen Sondheim, which is also available as a DVD, and an upcoming album with her longtime friend and onetime lover, Stephen Stills.

The two will embark on a tour together later this summer, and Ms. Collins said that Mr. Stills — who wrote the 1969 Crosby, Stills and Nash song sequence Suite: Judy Blue Eyes in her honor — likes one of her own recent originals, River of Gold. “I’m flipped out!” she said, laughing.

Ms. Collins’s audience can expect to hear old hits and newer tunes as well as songs by Mr. Sondheim, Tom Waits and the late Leonard Cohen.

“I’ll never stop singing Leonard,” she said.

Her Martha’s Vineyard performance is one of about 120 shows Ms. Collins plays each year. “I’ve pretty much been on the road for 57 years,” she said, and her stay on the Island won’t be long.

“I always hit and run, unfortunately, that’s my life,” she said with a laugh. “At least I get to breathe the air up there for a while.”

She performs at 8 p.m. June 8 at the Old Whaling Church in Edgartown. Ticket information is available at capecodshows.com or by calling 617-531-1257.