It’s an hour before the live broadcast of NBC’s musical “Hairspray Live,” and the show-within-the show is going through last-minute rehearsals. Darren Criss, who’ll be serving as the night’s “multi-platform host,” is running up and down Baltimore (a.k.a. New York) Street on Universal’s famed backlot, practicing the opening that will kick off the evening’s events. Just down the street, director Kenny Leon can be heard giving the cast a last-minute pep talk: “We’re on sacred ground,” he tells them.

Parked next to the main production truck is a clone, another satellite truck that’s serving as mission control for the live production elements that will add bells and whistles to what viewers see at home. A bank of screens show images from the cameras set up in the four cities with viewing parties around the country — from Baltimore (naturally) to Atlanta, Philadelphia, and Houston, star Maddie Baillio’s hometown. There are feeds from the dozens of cameras hidden in and around the soundstage and the street set, like in the rafters or behind the basketball net. “It’s an enhanced theatergoing experience,” Dave Dore, NBC’s SVP of digital creative, tells Variety. “They wouldn’t sell you the seat in the locker room.”

Fresh off his starring run in “Hedwig and the Angry Inch” at L.A.’s Pantages Theater, Criss was chosen for his appeal to the target demo for the musical. “We got really lucky,” Rob Hayes, NBC’s EVP of digital, tells Variety. “He’s a massive Broadway fan.” Criss was tasked with hosting several Facebook Live hits throughout the night, which went on to draw 2.8 million unique viewers. “His role is to be a surrogate for the fans,” adds Hayes. “He’s the viewer.”

This companion production was conceptualized alongside the actual show itself from the start, fully integrated into the show with the cooperation of live television director Alex Rudzinski. “We knew everyone was going to be watching the show with their phones in their hands,” says Dore.

The network’s digital team created custom experiences for every major social platform — from the Facebook Live show to a Snapchat live story. They also reached out to key social media “influencers,” inviting them to cover the performance from a platform built high above Baltimore Street. Their posts throughout the night across Instagram and Twitter generated more than 3 million interactions, according to data from NBC.

The network credits the social media push with ratings bumps for women between the ages of 18 and 24 (3.6) and female teens from 12-17 (3.3), although the show’s overall ratings fell to a 2.3, matching “Peter Pan Live.”

“I’ve never seen anything like this before,” says YouTuber Manny Gutierrez. “It’s all one moving thing, doing it in one take. The talent that’s here is so professional. They sing so well.” As for the social media integration, he’s a fan of networks embracing the efforts of him and his cohorts. “It’s a win-win for both of us. They get more promotion out of it. I hope they continue to do it. I’ll be here next year!”