It was Fleet Week in New York City, and something unusual was taking place on Billionaires’ Row. At 9 West 57th Street, an elegant black sloping skyscraper towering over the Plaza hotel and the half-dozen sailors congregated outside, 20 people were ushered into a small, glass-fronted gallery on the ground floor. A ferocious crimson Basquiat greeted them, along with a monochrome Kline and a serene Henry Moore – works collected by the building’s late owner, the real estate mogul Sheldon Solow.

The exhibition’s curator, Joseph Henry, silenced the excitable group. “You are the absolute first members of the public to come on a public tour,” he said, standing beneath an Alexander Calder mobile.

Under the watchful gaze of three sentinel security guards, Henry led the group on a swift, authoritative tour of the works he had brought together: a quartet of Cézannes, smudged in delicate blue and green; an angular mask carved by the Dan people of Ivory Coast, hanging next to a complementarily geometric Picasso; two Giacometti portraits with cockroach-coloured faces; three Miró dream paintings; a somewhat dingy Van Gogh. The tour ended after 35 minutes precisely, and a distinguished-looking gentleman with a Strand Bookstore bag asked: “So why were you closed for so long?”

“Closed for so long” implies the gallery was once open. It wasn’t. For years, the art could be glimpsed only from outside, beyond the glare of the windows. The collection, amassed by Solow, who died in 2020 aged 92 and worth $4.4bn, is conservatively valued at $500m. And while the majority of works were privately owned by Solow – and now by his son, Stefan Soloviev (who uses the pre-Ellis Island version of the family name) – a dozen or so of them are held by a tax-exempt non-profit called the Soloviev Foundation.

Set up by Solow in 1991 as the Solow Art and Architecture Foundation (and since renamed by his son), the non-profit describes its charitable activities in its tax filings: “The foundation maintains and displays artwork for exhibition to the public at the 9 West 57th Street, New York building.” While the gift of artworks like Matisse’s Acrobats (which is worth $30m) and Van Gogh’s Coal Barges ($50m) to the foundation entitled Solow to certain tax write-offs, they were not readily accessible to the public.

This completely legal set-up caught the eye of Ethan Arnheim, a Washington-based international development consultant, who created a parody website drawing attention to the foundation’s tax status and inaccessibility in 2017. He was outraged, but also, he said, hoped to “alert people to the fact that … you can do this questionable practice under current code”. A few of the artworks were technically on “public” display in the office building’s lobby (hardly an art-world destination) and some were lent to Museums, such as the Botticelli sold in 2021 for $92m (which spent many years at the Met) or a Miró triptych, which went to the Tate Modern in 2011. Although, as Arnheim pointed out, lending to museums is a common practice among collectors, since it increases the value of the works.

There are plenty of examples of art foundations that work well as private museums, such as Glenstone in Washington DC, the Broad in LA and the Rubell museums in Miami and DC. And there are plenty of generous patrons of the arts, like the Lauders or the Rockefellers, in New York City, said Robert Storr, former senior curator of painting and sculpture at MoMA and one-time holder of a professorship at NYU endowed by Sheldon Solow. (The foundation has made a number of large donations over the years, including gifts to NYU, $3m to the University of Rhode Island and, recently, $400,000 to another family-run non-profit, the Soloviev American Russian Cultural Foundation.)

But according to Storr, “the idea of a private museum is kind of an oxymoron, because a museum is a public space.” A museum does not exist in isolation, but rather in dialogue with its visitors, with its own collection and with the society it serves. Most of all, Storr emphasised, a museum is accessible: “A museum is its collection. If you can’t get to that collection, there is no museum.”

Private museums have come under scrutiny in the past, most notably in 2015, when the Republican senator Orrin Hatch led an inquiry into 11 tax-exempt private museums (the Solow Foundation was not one of them). Hatch concluded in a letter to the IRS: “Despite the good work that is being done by many private museums, I remain concerned that this area of our tax code is ripe for exploitation.” A Republican tax bill proposed a rule compelling private museums to be open a minimum of 1,000 hours a year, but it was not enacted.

The curdling of art into an asset class began some time ago, but such behaviour by the wealthy only crystallises the social stratification of the art world: “A lot of art is seen as esoteric and highbrow and inaccessible, and this behaviour only serves to reinforce that view,” said Arnheim. “Less people are going to want to go to museums when they can’t even get into museums and it’s perceived as just the bastion of the super-rich.”

Could some kind of democratisation be under way at 9 West 57th Street with the changing of the guard? Michael Hershman, CEO of the Soloviev Group, wrote in an email: “The reason for opening the collection to the public is social responsibility. It is a wonderful collection, and we want to share it with the public.” The opening was not, he added, “in any way driven by past criticism”, and the decision was taken by Stefan Soloviev.

Soloviev is no typical billionaire. The tattooed 47-year-old with a boyish undercut has 22 children. His fractious relationship with his father led him to move out west, where he built an agricultural empire that now places him among the top 30 largest landowners in the US.

Soloviev was not present at the opening, though Hershman was, smiling beatifically as he spoke to curious visitors. He was animated, but vague, as he spoke of the gallery’s future. “We’re in the process of sticking our toe in the water, if you like. Before we decide what to do next.” The gallery is undertaking something of a soft opening to the public, beginning with four tours a month, and the website gestures towards nebulous plans for an “expansion” in due course. (The Soloviev Group is one of several developers bidding for one of New York City’s three soon-to-be-granted casino licences. Its proposal, called “Freedom Plaza”, would develop a 6.7-acre plot of land by the United Nations, and includes a hotel, four acres of green space and a museum.)

For now, however, the gallery is open to whichever 20 lucky punters manage to score a spot on a tour. Vagueness aside, Arnheim is optimistic about the opening. “I don’t understand what their strategy is. But in the end, they’re doing the right thing, and that’s what’s important.”

For Storr, however, a few days a month is not good enough. “It’s grudging – you need to make a place where people feel comfortable coming in, and I know that many people feel uncomfortable even going to the galleries, which are free.” Indeed, the intrigue surrounding the collection as the result of its previous exclusivity may serve to further entrench a perception of art by well-loved artists as trophy collectibles for tycoons, rather than magnificent works for the city to revel in. Or, as Storr puts it, “just expensive things that somebody else owns and you get a chance to see”.

The reaction to the gallery’s opening on New York’s gallery circuit has been more ambivalent. Some stuck up their noses at its office-building location; some hadn’t even heard about it. For others, a lack of enthusiasm had more to do with the competition than the quality of the collection itself. As Ray Waterhouse, co-owner of the Upper East Side gallery Waterhouse & Dodd, pointed out, the city’s museums are stuffed with fabulous paintings. “So it’s somewhat irrelevant to the New York art landscape,” he said. “I’m not saying it’s not worthy.”

The art world has moved on from Solow’s mid-century taste. But there’s a value to the (intermittent) opening of a small, manageable collection of crowd-pleasers around the corner from MoMA and its long queues. With dynamic curation and a dramatic increase in the number of hours it’s open, the Soloviev gallery could come to be known for the quality of the art it houses rather than for its inaccessibility. As for the social barriers carefully built up by the collection habits of the international super-rich – that damage might take longer to unpick.

Not least in New York City, the art world’s financial capital. The tour ended with a glass of champagne in the building’s swanky subterranean restaurant, Cucina 8½. Afterward, I made my way past Bergdorf Goodman to the 59th Street subway station, where a man sat on the steps with a box of pastels and a cardboard sign which read: “Artist in need.”