Back in New York after an LA sojourn, he talks about breaking Basquiat, hanging with Haring, and never failing to put a “p” at the beginning of “arty”.

Mr Jeffrey Deitch is an enigmatic paradox, the personification of the art world’s opposing poles. As consigliere to the collecting elite, he is resolutely discreet about his clients’ multimillion-dollar deals. But as the godfather who helped propel Mr Jeff Koons to fame and launched the careers of countless young artists, he is an expert promoter, a showman. Even his Deitch Projects space in New York’s SoHo was one of the art world’s more hard-to-classify institutions, a gallery-project hybrid that routinely discovered new talent, ignored barriers between disciplines and diligently kept the art party going.

A recently released tome, Live the Art: 15 Years of Deitch Projects, chronicles the gallery’s rule-breaking run, which began in January 1996 with a performance by contemporary artist Ms Vanessa Beecroft featuring a gaggle of women standing about while clad in see-through skivvies and high heels, and ended in 2010 when Mr Deitch closed the business to accept the directorship of the Museum of Contemporary Art, Los Angeles. His tenure there was rocky, and he parted ways with MOCA in 2013, before his contract was up. He kept his spacious house in LA but has also resumed his ultra-high-end art advising and private dealing from the second floor of his former gallery. Keeping up his public profile as well, he is seeking out new art to exhibit and promote as ambitiously as ever.

Always impeccably dressed, Mr Deitch, 62, is wearing an Italian bespoke grey pinstripe suit on the cold morning when MR PORTER drops by. The crisp shirt is white, the collar spread, the cufflinks gold, the tie black. Topping off the look is his sartorial signature: eyeglasses custom-made in Germany, with round frames that dominate his face. He dons them, perhaps, with a wink; while their shape and prominence suggest the comically nearsighted Mr Magoo, Mr Deitch’s eye for art is obviously keen.

He gave first or early solo shows to multimedia artists Mses Mariko Mori, Tauba Auerbach and Miranda July; welcomed established artists such as Messrs Paul McCarthy and Francesco Clemente; and pulled off a surprise 50th birthday party for Mr Koons featuring a marching band and a pair of white ponies. As much impresario as dealer, he produced musical act Fischerspooner and encouraged Messrs Dash Snow and Dan Colen to trash his gallery by shredding 2,000 city phone books for one of their “hamster nest” installations, dousing the pile with wine, spray paint and urine.

Mr Deitch’s engaging prose snakes through the new book, narrating the gallery’s colourful history. In a savvy move to avoid hurt feelings, he dispensed with the standard cover image of a single artwork and affixed a plastic plate, a physical manifestation of the title, Live the Art. “It is the final Deitch Project,” he says of the substantial volume. “It is an artwork in book form.”

While plenty of galleries make more money trading on the secondary market than selling new art, Deitch Projects operated with an extreme model, commonly producing exhibitions with no work to sell whatsoever. Mr Deitch served as his own backer. “The Michel Gondry show, that cost me a fortune. We built an entire mini film studio [for the film director],” where visitors could shoot their own movies, he says. “There was nothing we sold. Some projects cost a million dollars. I was very fortunate that I didn’t have to make decisions based on what would sell. We inspired people.”

Mr Deitch grew up in Connecticut, graduated from Harvard Business School and first made his mark creating the art advisory service for Citibank’s wealthy, international clientele. To be sure, he knows his way around a studio visit. But long before Facebook, he perfected the art of social networking. He’d still rather spend quality time with movers and shakers than trudge to every global fair and biennale. His way of surveying the Chinese market, for instance, was to accompany restaurateur-cum-artist Mr Michael Chow for his opening at the Ullens Center for Contemporary Art in Beijing in late January. “Some of the most interesting art patrons invite me to spend a week with them,” he says. “I love the art, but I also love the people.”

Mr Deitch formed his early clique “organically”, he says, hanging out in lower Manhattan in the early 1970s. “You’d see Jean-Michel [Basquiat] sitting on a loading dock,” he says, “and you’d come and talk.” He was introduced to Mr Basquiat at a gig where the artist’s band, Gray, was playing. “Someone said to me, ‘That’s SAMO’,” Mr Deitch recalls, referring to the pseudonym Mr Basquiat used to tag the city alongside a few of his friends. Mr Deitch became the first to write about the paintings Mr Basquiat produced under his own name. He met Mr Keith Haring, known for his graffiti-infused paintings, at a party where Mr Haring was working as a bartender, and Mr Julian Schnabel when the painter was cooking at a basement joint.

Of the same generation, they were all easy friends. Nowadays, Mr Deitch frequently relies on younger contacts to make strategic introductions. “There are isolated individual talents, but if you go through the history of art, almost every innovation is part of an artistic dialogue,” he says. “You name it: cubism, German expressionism, there’s always a community. I try to find these centres of energy and connect in these social situations.”

When he accepted MOCA’s top job, the museum was already reeling. On the verge of financial ruin, the museum’s board had taken a bailout from Mr Eli Broad, the powerful collector with a reputation for demanding control. Mr Deitch’s background in “commerce” was met with skepticism. Eventually, artists Mr John Baldessari, Mr Ed Ruscha, Ms Catherine Opie and Ms Barbara Kruger all resigned from the board.

For his part, Mr Deitch is sanguine about his record at MOCA. “I had a great time there,” he says. “Everyone warned me, ‘Don’t go near it.’ I just charged in.” Contrary to press coverage, which tends to focus on Ms Marina Abramović’s use of live nudes as table centrepieces at a gala, he asserts, “it was a very deep programme”. He cites The Painting Factory: Abstraction After Warhol and the graffiti survey Art in the Streets, the museum’s best-attended show ever. He even defends his maligned collaboration with noted dilettante Mr James Franco, who, in the midst of a guest role on a daytime soap, convinced the writers to pen a storyline involving the museum. “We got General Hospital to build a set at the museum. I love the idea of bringing contemporary art to this mainstream audience. That’s the kind of art subversion I love.”

Mr Deitch used his perch to connect with well-heeled Hollywood types – “some special people” is his term – who have since transitioned to clients. They join renowned Greek collector Mr Dakis Joannou, as well as other global moguls Mr Deitch is far too tight-lipped to name. “I’ve had relationships with special families going back to 1980,” he says. “There are families I’m on the third generation of advising on their collection.”

While he is noncommittal about the possibility of operating a permanent space again, he is jazzed about plans to mount three shows in 2015 in New York and Europe: OVERPOP, focusing on recent art with roots in 1960s-era pop; a rendition of MOCA’s Art in the Streets; and Fire in the Disco, a show about the history of disco originally slated for MOCA, which some say was so lowbrow that it finally doomed his directorship.

Mr Deitch, however, has a very different take on the matter. “I resigned of my own volition,” he says. Moreover, he insists, he never lost the support of the board or its biggest patron. “While we were talking, an email came through from Mr Broad: ‘Let’s get together.’ I have to hang up now because Eli referred me to a collector, who I need to go meet.”