At age 11, Rudy Pensa sat at home in Argentina, flipping through music magazines and wishing he could shop at New York’s famous Music Row.

A guitar player, he saw it as a mecca: the block of 48th Street between Sixth and Seventh avenues that, since the 1930s, had been home to dozens of guitar sellers, studios and repair shops.

Rudy's was so happy have Dave Grohl in the shop that Rudy pulled out some of his favorite stash guitars to celebrate. #rudysmusic #foofighters #davegrohl #nirvana #59lespaul #burst A photo posted by Rudy's Music Shop (@rudysmusic) on Feb 23, 2014 at 1:04pm PST

For rock legends — Jimi Hendrix, Eric Clapton, the Rolling Stones, The Beatles — it was one-stop shopping for everything from pedals and sheet music to accordions and amps.

“Everyone bought their instruments on 48th. There was no other way,” says Pensa. He eventually made it to the city in 1971 — and immediately took a cab to the street to browse at stores like Manny’s and Sam Ash. He opened his own place, the four-floor guitar and repair shop Rudy’s Music Stop, on the block in 1978.

“It wasn’t America I wanted to come to,” he says. “It was 48th Street, which happened to be in America.”

No one will ever have that dream again, though. High rents and changing shopping habits have whittled the block down to a shadow of its former self. Pensa closed shop on Friday.

The last Music Row store, Alex Musical Instruments, is closing in a few months, owner Alex Carozza tells The Post.

Carozza’s landlord would have let him stay if he agreed to a rent increase from $4,000 to $12,000 a month. No thanks, says the shopkeep. By the end of the year, Music Row will officially be dead.

The biggest hit came in 2012, when Sam Ash — which operated half a dozen shops on both sides of the street, selling sheet music, brass, woodwinds, guitars and accessories — closed all those doors after 50 years. (The business relocated to 34th Street.)

The building owners shooed them out to build condos, Paul Ash, son of founders Sam and Rose Ash, told The Post at the time.

The former Sam Ash spaces sit mostly empty, as does the building that contained Manny’s, a store that displayed personal notes of thanks from Bob Marley and Bob Dylan before closing in 2009, after 76 years (the owners cited declining business as the cause).

After more than 50 years in business, New York Woodwind and Brass shop moved in 2013; a Dunkin’ Donuts moved in shortly after. The east end of the block is now full of office buildings, a Chipotle and Broadway’s Cort Theatre.

For the next few months, the remaining soul of Music Row will live on in Carozza’s shop, packed with old squeezeboxes and even an accordion “museum.”

Carozza, who speaks four languages, still has lots of customers around the world, and when you pop in the shop you might catch a mariachi band picking up an instrument from a tuneup.

The walls are a mini history of the store: photos of soccer superstar Pelé, former Sony Music head Tommy Mottola and Frank Sinatra, all of whom Carozza did business with.

Grumbling over disappearing New York history is becoming a cottage industry, but Carozza isn’t too emotional about it.

“No,” he says when asked if he’s sad to see it end. “The time comes for everything.”

Financially, he’s doing OK: Carozza got into the stock market and real estate years ago, buying several apartments and even a former Sam Ash building. He sold that to the Rockefeller Group for $33 million in 2008.

Over the years, Carozza, Pensa and other shop owners talked about trying to preserve the block as a historical district, but could never get any discussions with the city off the ground.

Pensa said he wanted to put Walk of Fame-style stars on the sidewalk commemorating the row’s famous clientele, and have guitar-shaped pillars welcoming people to the block, like the jewels at the entrance to the Diamond District.

Jeremiah Moss, the pseudonymous blogger behind Jeremiah’s Vanishing New York, which chronicles the changing city, calls the death of Music Row “a tragedy. When you have different districts you have a diverse city, where you move through the Flower District, the Diamond District, the Garment District. [NYC is] getting bulldozed by this wave of sameness.”

Pensa, who still has a Soho shop, tried to hold out against that sameness, but his rent had been too high for about five years already.

“I look at the numbers, I should have left before,” he says. “But I always had the romanticism, and the idea that it will come back.”