Izzy Young, whose Greenwich Village shop, the Folklore Center, was the beating heart of the midcentury folk music revival — and who in 1961 presented the first New York concert by a young Bob Dylan — died on Monday at his home in Stockholm. He was 90.

His death was confirmed by his daughter, Philomène Grandin.

Anyone wanting to capture the essence of the times could do far worse than head to the Folklore Center, at 110 Macdougal Street, between Bleecker and West Third Streets. Established in 1957, it was nominally a music store, selling records, books, instruments, sheet music and fan magazines, most sprung from sweat and mimeograph machines, like Sing Out!, Caravan and Gardyloo.

In actual practice, the center was also equal parts hiring hall; Schwab’s Pharmacy, where young hopefuls awaited discovery; matchbox recital space for organized performances and impromptu jam sessions; nerve center for gossip on a par with any small-town barbershop; and forum for continuing, crackling debate on the all-consuming subject of folk music, which thanks in no small part to Mr. Young was enjoying wide, renewed attention.

“I began hanging out at the Folklore Center, the citadel of Americana folk music,” Mr. Dylan wrote in his memoir “Chronicles: Volume One” (2004), recalling his arrival in New York in 1961. “The small store was up a flight of stairs and the place had an antique grace. It was like an ancient chapel, like a shoebox sized institute.”

Crackling loudest above the din was Mr. Young, who, with his horn-rimmed glasses, prodigious vocal capacity and bottomless cornucopia of opinion, was the platonic, genially abrasive New York nebbish from Central Casting.

“His voice was like a bulldozer and always seemed too loud for the little room,” Mr. Dylan wrote. “Izzy was always a little rattled over something or other. He was sloppily good-natured. In reality a romantic. To him, folk music glittered like a mound of gold. It did for me, too.”

Until he closed the shop in 1973 to move to Stockholm and start a similar center, Mr. Young reigned supreme as a handicapper (“The first few times I met Dylan, I wasn’t that impressed,” he said. “But as he began writing those great songs, I realized he was really something”); an impresario (he organized hundreds of concerts throughout the city, including Mr. Dylan’s first formal appearance, at the Carnegie Hall complex, as well as performances by the New Lost City Ramblers, Dave Van Ronk, Jean Ritchie and Phil Ochs); and an evangelist who almost single-handedly put the “Folk” in Folk City, the storied Village nightclub.

He was also a writer, with a regular column in Sing Out!; a broadcaster, with a folk music show on WBAI in New York; an agitator (in 1961, he helped organize successful public protests after the city banned folk music from Washington Square Park); a ferocious keeper of the castle (“He was even known to throw people out of his store,” Dick Weissman, a former member of the folk group the Journeymen, wrote, “simply because they irritated him”); and an equally ferocious defender of the faith. (Mr. Young repudiated Mr. Dylan after he began wielding an electric guitar in the mid-’60s.)

If, at the end of the day, the Folklore Center was a less-than-successful capitalist enterprise — who, after all, goes into folk music to get rich? — it scarcely mattered. Joni Mitchell was discovered there. Peter found Mary there, after seeing her photo on a wall. (Paul joined them soon afterward.) Mr. Van Ronk, then the more established musician, met the newly arrived Mr. Dylan there and invited him to take the stage at the nearby Gaslight Cafe.