Sylvain Sylvain, a key member of the New York Dolls, the influential though short-lived proto-punk band whose outrageous shows at Max’s Kansas City and other venues paved the way for the era of the Ramones and the Sex Pistols, died on Wednesday at his home in Nashville. He was 69.

His wife, Wanda O’Kelley Mizrahi, said the cause was cancer.

Mr. Sylvain had been dabbling in the garment business when he joined the fledgling group as a guitarist in late 1971. He had gone to high school in Queens with two of the other members, Johnny Thunders, the lead guitarist, and Billy Murcia, the drummer, a friend since childhood. And it was Mr. Sylvain who came up with the group’s name, based on something he saw out the window of Different Drummer, the Lexington Avenue boutique where he worked.

“Across the street was the New York Doll Hospital, a toy repair shop,” he told Lenny Kaye in an interview for the Bob Gruen photo book “New York Dolls” (2008).

“That’s where I first saw the name,” he added. “It made sense to me: That would be a great name for a band.”

The New York Dolls were brash and glam, gender-bending and unapologetic, qualities that were still a few years away from becoming commonplace in clubs like CBGB in the East Village.

“We had to rely on ourselves,” Mr. Sylvain told Mr. Kaye, “because of what was going on in the scene, which was nothing.”

David Johansen, the group’s lead vocalist, said Mr. Sylvain had been a vital part of the phenomenon.

“His style, grace and musicality, his buoyant personality and natural congeniality added an incalculable charge to the New York Dolls,” Mr. Johansen said by email. “He was the most passionate player I ever knew. Syl just loved performing, and would storm out on stage every night. He adored the audiences all over the world, and always made an effort to make himself available to them.”

The band made a quick splash but within a few years had dissolved, leaving only two albums from its heyday, “New York Dolls” (1973) and the prophetically titled “Too Much Too Soon” (1974, the title borrowed from the autobiography of the actress Diana Barrymore). It produced no radio-friendly hits, but its fame grew after the fact. As Mr. Sylvain put it in his memoir, “There’s No Bones in Ice Cream” (2018, written with Dave Thompson), “We were reborn as an historical precedent, year zero of punk, the Roanoke colonists of the new wave’s new world.”

Mr. Murcia died of an overdose while the band was touring England in 1972. Johnny Thunders died in 1991. Jerry Nolan, who replaced Mr. Murcia and played on the albums, died in 1992. Mr. Sylvain continued to perform with his own groups and with Mr. Johansen after the Dolls dissolved. In 2004 he, Mr. Johansen and the other surviving member of the Dolls, the bassist Arthur Kane, reunited for the Meltdown Festival in London, but Mr. Kane died of leukemia soon after.

Mr. Sylvain once summed up the band’s bittersweet arc.

“It was like a race, and we were like horses,” he said. “The Dolls were the number-one horse. We were right there, like two seconds away from the finish line, and behind us were the Ramones, Kiss, the Dictators and Blondie, and the list goes on. Then we fell and broke our leg and the next guy won the race.”

Sylvain Sylvain Mizrahi was born on Feb. 14, 1951, in Cairo. His father, David, a banker, was part of a family of Sephardic Jews originally from Turkey, and his mother, Marcelle, was of Syrian descent. The Suez Canal crisis of 1956, precipitated when Egypt’s president, Gamal Abdel Nasser, nationalized the canal, led to the family’s emigration.

“Nasser purged the country not only of British and French citizens and sympathizers, but also of Jews of every nationality,” Mr. Sylvain wrote in his memoir. “The Mizrahi family, my family, was just one of thousands caught up in the nightmare.”

The family moved to France and then, in 1961, to the United States, living in Buffalo before settling in Queens. Among those who befriended Mr. Sylvain there was Mr. Murcia, an immigrant from Colombia.

“Their two halves of broken English made a whole,” Nina Antonia wrote in “Too Much Too Soon,” a 2006 book about the band, “and they rapidly became inseparable.”

In the mid-1960s they began making sweaters, using a knitting machine, and built up a successful line under the name Truth and Soul. The two were also interested in music and admired a local band called the Orphans. When a member took an interest in Mr. Murcia’s sister, Mr. Sylvain recalled, “We told him if he wanted to meet her, he had to teach us how to play.”

They formed a loose-knit band, and other future members of the Dolls were drawn in. Mr. Sylvain went to Amsterdam for a time and was a bit miffed upon returning to find that Mr. Johansen and the others were playing under the name he had suggested.

“I got upset at that and gave them a little bit of my French,” he said in an interview for “Too Much Too Soon.” The group was rehearsing in a bicycle shop uptown at the time, and one of the guitarists “didn’t seem to have a lot of enthusiasm,” as Mr. Johansen put it in an interview for the Gruen book. Mr. Sylvain replaced him, playing opposite his old schoolmate Johnny Thunders, and the New York Dolls took off.

The band played a Tuesday night slot for weeks at the Mercer Arts Center, near Washington Square, as well as at Max’s and other spots, and toured the United States and Europe.

“In the early days on the road we always roomed together,” Mr. Johansen said. “He always knew the best inexpensive restaurants in every town on the planet, where the waiters treated him like a prince. He was really adept at languages, and uttered malapropisms in every tongue.”

In 2006 a new version of the Dolls featuring Mr. Sylvain and Mr. Johansen released an album, “One Day It Will Please Us to Remember Even This,” the first of several.

“Alongside characteristic, happily debased romps,” Will Hermes wrote of that record in The New York Times, “is a wistfulness and a sort of wisdom, plus a quality you could almost call spiritual.”

In addition to his wife, Mr. Sylvain is survived by a son, Odell, and a sister, Brigitte.

In his book, Mr. Sylvain said the Dolls had put him in mind of a Bugs Bunny cartoon in which Daffy Duck, tired of being outdone by Bugs in a stage show, seeks the audience’s applause by ingesting a toxic brew of explosives and blowing himself up.

“When you take the stage,” he wrote, “no matter who you’re sharing it with, you’ve got to promise to die. To detonate. To fly as high as you can and then, like the Fourth of July, explode like a sky full of fireworks.”