Willie Winfield, whose silken lead vocals with the Harptones in the 1950s made him a favorite of doo-wop connoisseurs, even though the group never achieved wide mainstream commercial success, died on July 27 in a hospital in Brooklyn. He was 91.

The cause was cardiac arrest, his daughter Tina Winfield said.

Mr. Winfield’s angelic voice was first heard in the early days of rock ’n’ roll, and he continued to sing when doo-wop groups turned into nostalgia acts in the 1970s. He toured with various incarnations of the Harptones until he retired in 2019, when he was 89.

“He had one of the best voices around,” Dick Fox, a producer who booked the Harptones dozens of times on his live oldies shows, said in a phone interview. “His voice was unique, and it lasted his whole life. He never lost the higher register.”

During the 1950s, Mr. Winfield and the Harptones performed at the Apollo Theater and at shows promoted by the influential disc jockeys Alan Freed (at the Brooklyn Paramount) and Murray the K (at Palisades Amusement Park in New Jersey). They were seen in the 1956 musical revue film “Rockin’ the Blues.”

Among the group’s best-known songs were “A Sunday Kind of Love,” “Since I Fell for You” and “My Memories of You.”

“Singing the songs for me feels fresh every time,” Mr. Winfield told the critic David Hinckley in a 1985 interview for The Daily News. “It’s the way people respond. All of a sudden, I forget my age. I lose all sense of everything except the song. I go back to the first time we recorded, when we had no idea what would happen.”

Robert Palmer, the chief pop music critic of The New York Times, wrote in 1982 that Mr. Winfield’s voice had “immaculate pitch and an insinuating way with a phrase.” And in a 2019 article on the website Medium, Mr. Hinckley wrote: “Willie Winfield is to rhythm and blues vocal group harmony music what Jackie Robinson and Mariano Rivera were to New York baseball. Top of the list. It’s not even a discussion.”

But despite Mr. Winfield’s memorable voice, the Harptones’ exquisite harmonies and the jazz-inspired arrangements of Raoul Cita, their pianist, they never reached the same level of commercial success that contemporaries like the Drifters, the Cadillacs and the Flamingos did.

Willie Lee Elijah Winfield was born on Aug. 24, 1929, in Surry, Va. His father, also named Willie, was a merchant seaman. His mother, Christine (Cooke) Winfield, was a homemaker.

Mr. Winfield sang in a church group in Norfolk and with his brothers Clyde and Jimmy. After he moved to New York in 1950, he and his brothers sang on street corners with two other men and practiced under the Manhattan Bridge.

In 1953, some members of another doo-wop act, the Skylarks, merged with some from the Winfield brothers’ group, forming a new group, which they first called the Harps and, soon after, the Harptones. In addition to Mr. Winfield and Mr. Cita, the lineup consisted of William Galloway, Billy Brown, Nicky Clark and William Dempsey. Mr. Dempsey is the only member of the original group who is still alive.

The Harptones “demand consideration in any serious discussion of the truly immortal acts of the doo-wop era,” Jason Ankeny wrote on the website AllMusic. But success proved elusive.

Charlie Horner, who runs the Classic Urban Harmony website, said in an interview that the Harptones were popular in New York and other cities in the Northeast, as well as in Chicago, but that their local successes did not add up to any national hits.

However, he said, if Billboard’s rhythm-and-blues chart had a Top 100 (instead of a Top 10 or 20) during the Harptones’ most productive years, in the mid-1950s, they might have had as many as 10 hits. Their only chart hit, “What Will I Tell My Heart,” peaked at No. 96 on the Billboard Hot 100 in 1961.

The fact that the Harptones recorded for a succession of small labels with limited distribution did not help their cause.

“At one time we decided to try to promote our own records,” Mr. Winfield said in the Daily News interview, which Mr. Hinckley repurposed last week on the Medium website. “It was like, give the D.J. $75 to play the record. Our producers should have been taking care of that.”

In the mid-1960s, Mr. Winfield began delivering prayer cards to funeral homes; he retired from that job in 1995. He continued to perform part time with versions of the Harptones, notably as background vocalists on “René and Georgette Magritte With Their Dog After the War,” a tender song on Paul Simon’s album “Hearts and Bones” (1983) that recalls the doo-wop music that Mr. Simon grew up listening to.

In addition to his daughter Tina, Mr. Winfield is survived by another daughter, Stephanie Winfield; his sons, Vincent, Timothy and DeWayne; two sisters, Serita Alexander and Goldie Bronson; two brothers, Clyde and Abraham; 44 grandchildren; and 22 great-grandchildren. His wife, Alice (Battle) Winfield, died in 2011.

At Mr. Winfield’s final performance, at a doo-wop weekend in April 2019 at Half Hollow Hills East High School in Dix Hills, N.Y., he wrapped up his career with another signature ballad, “Life Is But a Dream.”

He sat on a stool until the end of the song and, after the group sang “Will you take part in,” he rose, steadying himself on his cane, and finished the line and the song in his familiar tenor — “my life … my love? That is my dream.”

And he hit the high notes.