“The Book of Hov,” an elaborate summer exhibition at the borough’s main branch, was quietly conceived by his team as a surprise tribute that opens Friday.Earlier this week, when passages of Jay-Z lyrics from songs like “Hard Knock Life (Ghetto Anthem)” and “Justify My Thug” appeared on the Art Deco-style, curved limestone facade of the Brooklyn Public Library’s main branch, fans and passers-by could only speculate on the occasion for the building’s sudden makeover. A surprise concert for the rapper’s home borough? A tribute to the 50th anniversary of hip-hop this summer?The answer, it turned out, was neither — and also a secret even from the man himself.On Thursday evening, when Jay-Z entered the library for a private event surrounded by an inner circle of family, friends and business associates, he was greeted by his live band playing instrumental versions of his hits out front, and a career-spanning archival exhibition that he never asked for inside.Jay-Z learned about the exhibition at a private event held at the library on Thursday night.Simbarashe Cha for The New York Times“I know he wouldn’t let us do this,” said Desiree Perez, the chief executive of Jay-Z’s entertainment empire Roc Nation, about keeping such elaborate plans from the boss. “This could never happen if he was involved.”Featuring artwork, music, memorabilia, ephemera and large-scale recreations of touchstones from a sprawling career, “The Book of Hov,” which will run through the summer, might seem more at home at the Brooklyn Museum down the block. But by installing the showcase across eight zones of a functioning library, its architects are aiming to bring aspirational celebrity extravagance to a free public haven just a few miles from the Marcy Houses where Jay-Z grew up.“Jay belongs to the people,” Perez said. “It’s a place that feels comfortable. It’s not intimidating. A lot of people go to the museum, but a lot of people don’t.”Nicola Yeoman and Dan Tobin Smith’s mash-up of instruments that was photographed for the “Blueprint 3” cover.Amir Hamja/The New York TimesA Gucci jacket tied to the release of Jay-Z’s 2010 memoir, “Decoded.”Amir Hamja/The New York TimesA mural by Jazz Grant made of hand-cut and scanned imagery from Jay-Z’s archives.Amir Hamja/The New York TimesOnly the debut on Thursday was meant to be exclusive. Following a private tour through his own memories, Jay-Z made himself scarce when the tightly controlled doors opened, content to leave the V.I.P. guests among representations of his many likenesses, from Mafioso M.C. to boardroom mogul to social justice string-puller.Even his elusive wife, Beyoncé, mingled more, at least momentarily, as crowds gathered outside to catch glimpses of the Jay-Z extended universe — athletes like Jayson Tatum and Robinson Cano; the musicians Lil Uzi Vert, DJ Khaled and Questlove; the director Josh Safdie and the businessman Michael Rubin.By Friday, when the exhibit opens to the masses, the hors d’oeuvres and passed drinks — Jay-Z’s brands, naturally — would be gone. But remaining among the stacks are statues, sneakers, paintings, platinum plaques, trophies and news clippings tied to Jay-Z’s 13 albums and the companies he founded, including Rocawear and Tidal.The library had initially pitched Jay-Z as an honoree for its annual fund-raising gala. But when its chief executive, Linda E. Johnson — the wife of another Jay-Z ally, the developer Bruce Ratner — floated the idea to Perez of Roc Nation, the pair pivoted.One area of the library features playable turntables and vinyl representing the samples used across Jay-Z’s catalog.Amir Hamja/The New York Times“I just asked her, ‘How big is the library?’” Perez recalled. “And when she said 350,000 square feet, I couldn’t believe it.”Throughout the pandemic, Perez and Roc Nation had been plotting to display artifacts that conveyed Jay-Z’s influence across music, business and broader culture, including the pallets’ worth of master recordings he had regained ownership of over the years.“That archive belongs in Brooklyn,” said Johnson, who oversaw the merger of the Brooklyn Public Library and Brooklyn Historical Society.Together, the teams began planning “The Book of Hov” in January, tapping the production designers Bruce and Shelley Rodgers, Emmy-winning veterans of the Super Bowl halftime show, as well as the creative agency General Idea to conceive and execute the elaborate project.It wasn’t just displaying memorabilia. Beyond the library’s main atrium, beneath an enormous Jay-Z collage, now sits a full-scale replica of the main room from Baseline Recording Studios, where Jay-Z created some of his best-known songs. Every detail had to be correct, down to the TV size and the tub of Dum Dums on the counter.A full-scale recreation of the main room from Baseline Recording Studios, where Jay-Z created some of his most famous songs.Amir Hamja/The New York TimesA reel-to-reel machine in the replica of Baseline Studios.Amir Hamja/The New York TimesA Betacam master tape of the song “99 Problems.”Amir Hamja/The New York Times“They had the wrong couch, the wrong soundboard,” said Juan Perez, a Roc Nation executive and longtime friend of Jay-Z’s, who designed the original studio and gave plenty of notes for the recreation.Another area of the library features playable turntables and vinyl representing the samples used across Jay-Z’s catalog, surrounded by the encased tape reels, floppy disks and CDs containing his original music.Bruce Rodgers, the production designer now working on his 18th Super Bowl halftime show, called the project “probably the most intense installation I’ve ever been involved in,” adding: “We didn’t want to interrupt the normal workings of the library, but we wanted to make a statement.” That included flying in “ninjas” from the West Coast who could rappel up and down the building to install the lyrical facade in time.An area of the exhibition designed for children to make paper planes.Amir Hamja/The New York TimesThe paper plane is a Roc Nation logo attached to an inspirational motto.Amir Hamja/The New York TimesPart of the exhibition is dedicated to Jay-Z’s philanthropy and social justice work, as well as his various businesses.Amir Hamja/The New York Times“People thought I was a little out of my mind,” Johnson, the library executive, said. “I don’t think I’d be going out on a limb to say that this is the biggest exhibition we’ve ever done.”While the valuables will require additional security, Brooklyn Public Library was not paying for any of the production for the show, she added. “Roc Nation is doing a lot for us financially,” Johnson said, including a substantial donation tied to the gala in October, when Jay-Z and his mother, Gloria Carter, will be honored.In the meantime, Jay-Z will also be helping, perhaps unwittingly, with sign-ups. In addition to the draw of the exhibition itself, the library is producing 13 limited-edition library card variations featuring its homegrown star — one for each album.“I’m concerned about crowds,” Johnson said, conveying equal parts trepidation and excitement. “We’ll run out, I suspect.” More