The original vision also included Beyonce, Rihanna & host James Corden.

If ever there was a love letter presented at the Grammys, it was Adele's tribute to George Michael on the 2017 edition, during which she performed his 1996 song "Fastlove."

As a fellow Brit who was enamored with his music, Adele explained backstage following her awards sweep that she was "about 10" years old when she first discovered "Fastlove" and "heard the vulnerability in that song."

Added Adele: "When the video came out for that, I was blown away by how f---ing hot he was. It’s actually quite exceptional how good-looking he was."

She connected with the lyrics, Adele noted, which reference promiscuity but also point to losing one's way.

An iconic figure in their native United Kingdom, George Michael's Christmas Day death "devastated" Adele, she said. "I actually had to go for a walk on my own and just breathe for a while."

So how did that swell of emotion turn into a musical and visual Grammy tribute? According to Adele, "[The family] didn’t want a tribute at first, and they came back and were very specific that it be me."

The show's executive producer Ken Ehrlich, who had worked with Michael a number of times in the past, confirms, "The dream was Adele -- we had to get it right."

Michael Lippman, Michael's longtime manager, also had a dream: Grammy host James Corden, whose "Carpool Karaoke" series was launched with Michael in the passenger seat, Adele, Beyoncé and Rihanna, each taking a song of a different tempo and era ("Freedom" and "One More Try," among them) in one giant Michael mash-up -- an idea that began to take root, says Ehrlich. But it became quickly evident "how passionate Adele was," Ehrlich adds, "and that she had a vision for what she wanted to do with it."

With her manager, Jonathan Dickins, inching the endeavor forward, and Columbia Records chief Rob Stringer, himself a longtime associate of Michael's, in full support, Hans Zimmer was recruited as the arranger and conductor for the performance. Within a week, he had a recorded orchestral track ready to go. The mastered version was furnished to Grammy producers only on Thursday, some 72 hours before the curtain went up.

Adele was incredibly hands-on when it came to how the performance would be presented, multiple Grammy insiders tell Billboard. "It was important to her and she was fully committed," says Ehrlich, who reveals that Adele collaborated with Michael representative David Austin on the images and video used as visuals for the performance. "They corresponded directly about changes or thoughts she had," he adds.

Columbia's Stringer, who worked with Michael on three albums while head of Sony U.K., also helped make the tribute a reality. "To anybody who's British, George is like royalty," he tells Billboard. "He's right up there with Elton John and Paul McCartney and Freddie Mercury. He was loved."

The incoming Sony Music CEO passed through Goring-on-Thames, where Michael last lived, while on a recent trip to England and was amazed by the "massive shrine" outside the late singer's home. "I was a massive fan," Stringer recalls. "In college, Wham! were a big group. What a remarkable talent. For all of his idiosyncrasies and his pain, people loved him in the U.K. His music was the soundtrack to all of us growing up. For a good 10 years, he was the biggest artist in the world."

Indeed, Adele said as much backstage following her show-stopping bow. "I found him to be one of the truest icons, because a lot of the time, with people who are at that globally known and famous, there tends to be… not a fakeness in a bad way, but they put on this massive bravado and alter-ego to protect themselves," she elaborated. "And he was very British. No matter where his career or love life took him, he always remained true to Britain and they gave him a hard f---ing time a lot of the time, but he still stayed loyal until the very end. ... I relate to that -- no matter how much I try to escape Britain sometimes, my roots are there. I took great comfort in him -- and the bigger my career got, in trying to remain myself.

"It was an honor."