The Buku Music + Art Project, one of the younger, more rambunctious siblings of the New Orleans festival family, got off to a soggy yet spirited start Friday at Mardi Gras World.

The Buku grounds along the Mississippi riverfront consist mostly of concrete. Thus, despite Friday’s early rain and persistent drizzle, Buku avoided the fate of the 2015 Voodoo Experience, which canceled its final day after downpours rendered much of the City Park festival grounds a muddy bog.

By contrast, Buku was wet but still walkable. Once attendees traversed a swampy, slushy field to reach the entrance, the site was mostly free of standing water.

By late afternoon, long lines had formed at security checkpoints. Guards checked IDs — only those 18 and older were admitted — before attendees passed through metal detectors. “Everybody here been to court?” said a guard with a bullhorn. “It’s the same process.”

Buku sold out all 15,000 tickets for both Friday and Saturday despite plenty of competition this weekend, including St. Patrick’s Day parades and the rap-rock band 311’s two-night 311 Day celebration at the Smoothie King Center. The 2016 Buku is the event’s third sellout in five years.

The crowd skewed heavily toward hip-hop and electronic dance music fans in their 20s. They hustled among Buku’s multiple stages as tankers and cargo ships glided by on the Mississippi River.

Inside the massive Float Den, the King Kong and Mrs. Kong floats from Bacchus — adorned with Buku-patterned butterflies — watched stoically as DJ Mija presided over an uptempo dance party.

The lower half of the warehouse’s cross-thatched steel girders were wrapped in plastic sheeting to discourage climbers. About 3,000 people danced on a cement floor slick with humidity.

One food booth featured the culinary creations of Big Freedia, the New Orleans bounce rapper and reality TV star. They included “twerk-a-mein,” Freedia’s version of the noodle and beef soup yaka mein, renamed for the rump-shaking dance.

As the setting sun colored lingering clouds a fiery orange over the main outdoor Power Plant stage, the Scottish trio Chvrches delivered a buoyant set of electro-pop that recalled Madonna’s synthesizer-heavy hits of the mid-1980s. Lead singer Lauren Mayberry was undeterred by the weather. “We are super-used to rain because it rains all the time in our country,” she said. “We are like, ‘Ah, home.’ ”

Despite what many New Orleans music fans might consider to be an unfamiliar roster, Buku is very much a homegrown affair, albeit with its own aesthetic.

Buku founders Dante DiPasquale and Reeves Price entered the concert promotion and festival production business while still students at Tulane University. They staged the first Buku in 2012. Last year, international entertainment conglomerate AEG Live, which co-produces the New Orleans Jazz and Heritage Festival, acquired a portion of Buku; DiPasquale and Price are now AEG vice presidents.

Local sounds factor into Buku’s mix. Veteran rappers Mystikal and Juvenile performed back-to-back Friday on the indoor Ballroom Stage. Melissa “DJ Soul Sister” Weber spun her old-school vintage vinyl at the Back Alley stage.

South Louisiana alternative pop band Givers and local electronic music DJs Tristan Dufrene and Zack “Fro-Yo Ma” Villere are on Saturday’s bill. Members of the Preservation Hall Jazz Band are scheduled to join the EDM act Pretty Lights to close the Power Plant stage on Saturday.

Marquee names are not Buku’s main attraction. Instead, the festival offers a carefully curated, cutting-edge roster and an immersive experience in a uniquely urban, uniquely New Orleans setting.

The main outdoor stage is framed by a VIP riverboat docked on the Mississippi and the twin smokestacks of a long-abandoned power plant. Street performers and art installations sprinkled throughout the site enhance its other-worldly quality.

Organizers kept a watchful eye on the weekend weather forecast and urged attendees to “come prepared with rain gear such as ponchos or raincoats and rainboots.”

But unlike many area schools and some businesses, Buku did not pull the plug prematurely. Friday’s weather turned out to be not nearly dramatic enough to discourage the “Bukrewe.” Reveling in rain gear was the order of the day.

Follow Keith Spera on Twitter, @KeithSpera.