When asked about his musical ability, Henry Goldrich would often demur, “I play cash register.”

His stage was Manny’s Music in Manhattan, where Mr. Goldrich, the longtime owner, supplied equipment to a generation of rock stars. But even though he sold instead of strummed, Mr. Goldrich secured an important role in rock by connecting famous musicians with cutting-edge equipment.

“To these guys, Henry was the superstar,” his son Judd said. “He was the first guy to get gear they had never seen before.”

Mr. Goldrich died on Feb. 16 at his home in Boca Raton, Fla. He was 88.

His death was confirmed by his other son, Ian, who said he had been in frail but stable health.

Manny’s, which closed in 2009 after 74 years in business, was long the largest and best-known of the cluster of music shops on the West 48th Street block known as Music Row.

It was opened in 1935 by Mr. Goldrich’s father, Manny, and it was a second home for Henry since his infancy, when the shop’s clientele of swing stars doted on him. Ella Fitzgerald would babysit for him in the shop when his parents went out for lunch, Ian Goldrich said.

By 1968, when his father died at 62, Henry Goldrich had largely taken over operations and had turned the shop into an equipment mecca and hangout for world-renowned artists.

He did this by expanding its inventory of the latest gear and by solidifying connections with suppliers that helped him consistently stock high-level instruments and new products.

At a time before rock stars were lavished with the latest equipment straight from the manufacturers, Manny’s was favored by top musicians searching for new gear and testing out new equipment.

These included two guitar gods of the 1960s, Jimi Hendrix and Eric Clapton — to whom, Ian Goldrich said, his father recommended the wah-wah pedal, an electronic device that immediately became a staple of both musicians’ approaches. He added that Hendrix would buy scores of guitars on credit and have Mr. Goldrich fine-tune them to the guitarist’s demanding preferences.

Many rock and pop classics were either played or written on instruments sold by Mr. Goldrich.

John Sebastian, founder of the Lovin’ Spoonful, recalled in an interview how Mr. Goldrich in the mid-1960s helped him select the Gibson J-45 he used on early Spoonful recordings like “Do You Believe in Magic?”

Mr. Goldrich similarly matched James Taylor with a quality Martin acoustic guitar early in his career, his son Ian said. And Sting used the Fender Stratocaster Mr. Goldrich sold him to compose “Message in a Bottle” and many other hits for the Police before donating it to the Smithsonian Institution.

In 1970, he sold the Pink Floyd guitarist David Gilmour the 1969 black Stratocaster he played on many of the band’s seminal recordings. It sold at auction in 2019 for a record $3,975,000.

Pete Townshend of the Who would order expensive electric guitars by the dozens from Mr. Goldrich, who was not happy when he heard about the guitarist’s penchant for destroying his instrument onstage for theatrical effect.

“It was good business,” Ian Goldrich said, “but my father was annoyed that Pete was breaking all the guitars he was selling him.”

Unlike many of his flamboyant rock-star customers, Mr. Goodrich always dressed conventionally in a sport coat and kept a blunt demeanor that put his customers at ease.

“He had a gruff personality; he treated them all the same,” Ian Goldrich said. “He’d tell Bob Dylan, ‘Sit in the back and I’ll be with you in a minute.’”

There was the day in 1985 — it was Black Friday, and the store was packed — that Mick Jagger and David Bowie stopped by together, creating a commotion that halted sales. An annoyed Mr. Goldrich quickly sold them their items and rushed them out.

“My father was like, ‘What are you guys doing here today?’” Ian recalled. “He didn’t throw them out, but he was not happy.”

When the band Guns N’ Roses asked to shoot part of the video for their 1989 hit “Paradise City” in the store, Ian Goldrich recalled, his father agreed only reluctantly, saying, “OK, but we’re not shutting down for them.”

Ever opinionated, Mr. Goldrich told Harry Chapin in 1972 that his new song “Taxi,” at nearly seven minutes, was too lengthy to be a hit. (It reached the Top 40 and is now considered a classic.) And he told Paul Simon, who as a boy had bought his first guitar at Manny’s, that he thought Simon and Garfunkel was a “lousy name” for a group.

But he also advised new stars in a fatherly way not to squander their newfound wealth.

“He’d take them aside and say, ‘You’re making money now — how are you going to take care of it?’” Ian Goldrich said.

Henry Jerome Goldrich was born on May 15, 1932, to Manny and Julia Goldrich, and grew up in Brooklyn and in Hewlett on Long Island. After graduating from Adelphi College, he served in the Army in Korea in the mid-1950s and then went to work full time at Manny’s.

His father opened the store on West 48th Street, a location he chose because it was close to the Broadway theaters and the 52nd Street jazz clubs, as well as numerous recording studios and the Brill Building, a hub for music publishers. In 1999, Mr. Goldrich sold Manny’s to Sam Ash Music, a rival store, which largely retained the staff until Manny’s closed in 2009.

In addition to his sons, Mr. Goldrich is survived by his wife, Judi; his daughter, Holly Goldrich; seven grandchildren; and a great-granddaughter.

Mr. Goldrich often used his celebrity clientele to market the store. “He recognized value of these people being in the store and it made the business, certainly,” his son Judd said.

When a young Eric Clapton, then with the group Cream, was stuck in New York without the money to fly home to England, he offered his amplifiers to Mr. Goldrich to raise funds.

“He said, ‘I’ll buy them from you as long as you stencil them with the Cream logo,” Ian said.

Then there was the store’s Wall of Fame, thousands of autographed publicity photos of famous customers that constituted a Who’s Who of popular music. Mr. Goldrich helped cultivate the photos, many of which were inscribed to him, and often kept his staff from stacking merchandise in front of them.

Mr. Taylor, in a video interview, described being mesmerized by the photos as a teenager and being proud when his own was added. “It was sort of an inside thing, not as celebrated as a Grammy or a gold record or a position on the charts,” he said. “But definitely you had arrived if you were included on that wall.”

Mr. Goldrich became close friends with many musicians, including the Who’s bassist, John Entwistle, who attended Judd’s bar mitzvah in New Jersey and hosted the Goldrich family at his Gothic mansion in England. Ian remembered the band’s drummer, Keith Moon, sitting on his father’s lap while drinking cognac at a screening of the film “Tommy.”

In a video interview, Mr. Goldrich described selling the violinist Itzhak Perlman an electric violin. When Mr. Perlman tried bargaining, Mr. Goldrich parried by asking if he ever reduced his performance fee.

“He said, ‘It’s different, I’m a talent,’” Mr. Goldrich recalled. “I said, ‘I’m a talent in my own way, too.’”

That talent was palpable to Mr. Sebastian when he asked Mr. Goldrich to allow him to test out his stock of Gibson acoustic guitars in a merchandise room.

“Henry’s famously prickly demeanor receded slightly,” Mr. Sebastian recalled, and he agreed to open early the next morning to allow him in.

“He knew exactly what I wanted,” he said. “And I’ll be damned if I didn’t catch Henry smiling as he made out the bill.”