It all started with a phone call, in 1998, about an entirely different project.

Country superstar Garth Brooks was one of the biggest names in country music -- one of the biggest names in music, period -- and he needed songwriter and producer Gordon Kennedy to add guitar to "Tearin' It Up (and Burnin' It Down)" on his Double Live album.

Kennedy came to the studio. He played with "this guy who just came here from Australia," Keith Urban (they "got along fabulously," Kennedy remembers). Their job done, Kennedy was headed out when Brooks stopped him -- "kind of an, 'Oh, by the way ...' [thing]," the musician remembers.

"'I need some songs from you. It's for a movie,'" Kennedy recalls Brooks explaining, sharing a few details about the character and the film. "'I need songs to represent that artist's career ... You know, that stuff that you do: Beatles, Eagles' -- he might have thrown out some more references."

Kennedy, then with Polygram Publishing, "made a beeline for the publishing company." He pulled demos -- eight, 10, 12 songs or so -- put them on a CD and delivered them to Brooks. The star called him back within the hour, to put a song -- "number three or two or whatever it was" -- on hold.

"I remember thinking, 'The one I would have bet on would have been song number five,'" Kennedy recounts. "And then he called back 30 minutes later to put that song on hold ... so he was listening to them in his car and calling."

And so, Chris Gaines -- his musical history, at least -- was born. Of the 13 songs on 1999's Garth Brooks in ... The Life of Chris Gaines, Kennedy wrote 10 of them, eight with his friend and fellow songwriter Wayne Kirkpatrick. Brooks also dug into the catalog of their collaborator Tommy Sims, who is a writer on five of the Gaines tracks. With the exception of one song ("Right Now," which combines verses by Cheryl Wheeler with the chorus of folk-rock band the Youngbloods' 1960s hit "Get Together"), at least one of the three men had a hand in every one of the Gaines songs.

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Kennedy and Kirkpatrick ran in Brooks' circles for years before they began working on the Gaines project: Kirkpatrick worked with a Christian singer named Susan Ashton, whom Brooks took on tour in Europe in the mid-'90s, while Kennedy's brother Bryan, also a songwriter, knew Brooks from Brooks' early days in Nashville.

In fact, in the early '90s, Bryan Kennedy had given Brooks a four-song demo tape from Kennedy and Kirkpatrick, then known together as the Mute Brutes of Labor and working to get a record deal with a New York City-based label. The label passed on signing the pair -- "We just don't hear the hit," Gordon Kennedy says label execs told them -- but three of the songs on that demo, "White Flag," "Digging for Gold" and "My Love Tells Me So," would, years later, make their way onto the Gaines album. (A fifth song they pitched the label, "Change the World," became a mega-hit for guitar god Eric Clapton.)

"He'll listen to a song for a long time and keep something in the 'grocery cart' until it's time," Kennedy says of Brooks. "He listens to a lot of music."

For the most part, what listeners hear on the Gaines album is what Kennedy, Kirkpatrick and company originally recorded, occasionally with a slight key change or extra instrumentation (for example, the orchestra on "Maybe"). Brooks wouldn't let them re-record, as Chris Gaines is supposed to be a greatest hits collection from throughout the fictional star's career. Creating new tracks would have made the songs sound too consistent.

In addition to "Right Now," two other Chris Gaines songs were written specifically for the project: "Unsigned Letter" -- a song that, in the Gaines universe, was inspired by a nurse whom Gaines fell for while in the hospital recovering from a car accident -- started as a demo from Kennedy and Kirkpatrick, and Brooks asked for some alterations. "Main Street," meanwhile, was a totally fresh write -- but not with credited co-writer Trisha Yearwood.

"The first three times that we wrote with Garth, he didn't put his name on the song ... so I don't know if that's his version of giving somebody flowers or what," says Kennedy. Brooks and Yearwood weren't married at the time, but they were longtime friends and collaborators. "For all I know, she said something to him, and he thought, 'That's a great song idea,' and then he contributed to it," Kennedy adds.

WATCH: Chris Gaines' Backstory is WILD!

The first song Brooks recorded for The Life of Chris Gaines was its lead single, the Billboard Top 5 "Lost in You." The album's producer, Don Was, hadn't arrived in town yet, so Kennedy and Kirkpatrick were the ones in the studio with Brooks as he took his first stab at the song, which finds him singing in a falsetto -- far outside what fans had come to expect from him.

"Wayne and I kinda braced ourselves for, 'We're gonna find something, for the first time in this guy's life, that isn't gonna work,'" recalls Kennedy. Adds Kirkpatrick, "My first thought was, 'He's gonna ruin this.'"

"And he starts singing this song, and our jaws hit the floor," Kennedy continues.

In Kirkpatrick's studio, they created a rough mix of the song, and later played it for Was, without revealing that it was Brooks singing. Was had no idea until the three men told him.

According to Kennedy, the original plan was to release the Gaines material without tying it to Brooks; however, "the record label, I think, got nervous about that," he says. "They thought using the name of Garth Brooks was going to catapult this into the stratosphere." And with Brooks at the height of his popularity, who could argue with that?

Of course, the exact opposite thing happened: Despite an NBC special introducing the world to Gaines, a fake Behind the Music episode sharing his backstory and Saturday Night Live episode during which Brooks hosted as himself and performed as GainesThe Life of Chris Gaines sold only 2 million copies -- nothing in comparison to the millions of copies Brooks' other albums sold. No one quite knew what to do with this music, performed by a country megastar playing a fictional pop-rock megastar who was a character in a forthcoming movie (that never got made).

Brooks talked plenty about Gaines in public, but he only assumed the role once, during that SNL performance. Even on the NBC special, he performed the Gaines songs, but dressed as himself; he talked the talk but didn't walk the walk, so to speak.

"I was standing on the side of the stage ... and I just remember standing there, and I am deeply involved in this project ... and now I'm confused," Kirkpatrick recalls. "And so, if I'm confused, then everybody's gonna be confused.

"It had so many great ideas ... and then he didn't really play out the character," he adds. "It was just a big head-scratcher when it came out."

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Sitting in a coffee shop in Nashville a few weeks out from the 20th anniversary of the Sept. 28, 1999, release of The Life of Chris Gaines, Kirkpatrick muses, "Garth has this approach of, 'I can do anything and everything,' to his credit. It's why he is what he is. But, you know, every genre can tend to have its exclusive club, so it's like, 'We love you over here, but you don't have a membership card for [this other] club, and we're not going to give you one so easily.'"

Kennedy has another theory: In addition to selling millions of albums, racking up No. 1 hits, selling out concert after concert and winning awards left and right, Brooks had also been to Spring Training with the MLB's San Diego Padres in 1998 and '99, ostensibly to raise money for and awareness of a sports-focused children's charity he had launched. Though he didn't make the team, pretty much everything Brooks touched turned to gold (or, more accurately, multi-platinum).

"What I saw at the time, from just being near the center of what was going on with him, was that there was this artist that the whole town rallied behind ... and they watched him become this gigantic thing," Kennedy says, "and then I can see ... I think at some point, it became, 'Well, he's a little too successful.' I could just see that human nature kicking in."

Brooks-as-Gaines may have inspired confusion and skepticism, but selling 2 million copies is no small feat, even in 1999, when the CD business was booming. In addition to its Top 5 Billboard ranking, "Lost in You" was recently covered by hip-hop artist Childish Gambino, and other songs from the project have been covered by Don Henley ("It Don't Matter to the Sun") and Alison Krauss ("Maybe"), among others. Of the 310 people who have reviewed The Life of Chris Gaines on Amazon, 83 percent of them gave the album four or five stars.

"The thing I always say about it is simply this: Everybody that heard it loved it. Everybody else hated it," says Kennedy from his home studio. (The Life of Chris Gaines is, in fact, Trisha Yearwood's favorite Brooks album.) "I never saw [the criticism] as anything about how bad the music was; it was all about, 'What are you trying to do?'"

Kirkpatrick agrees, noting that those involved with the project "felt good about the record."

"Everybody that was making the record felt like it was a solid piece of work. We weren't kind of shielding our eyes," he reflects. "Everybody involved were quality musicians, quality engineers and writers and all that kind of stuff. We were putting our best foot forward ... All of these songs were songs that we were trying to get a record deal with [in the early '90s], so we were putting our best foot forward in that phase of it, too."

What Ever Happened to That Chris Gaines Movie Anyway?

It's easy to get caught up in the "what if?"s and hypotheticals of Brooks' turn as Gaines: What if the project had been released anonymously? What if Brooks had "gone pop" and released the album under his own name? What if the movie featuring Gaines, The Lamb, had actually been released? What if The Life of Chris Gaines was released today, in a time when crossovers and common and the lines between genres are blurring?

"To expect everything to stay in its place is not really the message of the modern world ... and so maybe Chris Gaines, that would have been accepted a little more today, I don't know," Kirkpatrick reflects. "I think some of it is, I don't know if the public felt like 'We're being conned here,' or 'You're trying to pull a fast one on us' ...

"I mean, Shania Twain is Def Leppard with a fiddle ... and, of course, it's the same producer [Robert John "Mutt" Lange]," he adds. "But it was Shania Twain doing it, [not an alter ego]."

Kennedy doesn't think about that much. Like his tour boss (Kennedy is currently playing with Brooks on his Stadium Tour), he prefers to keep looking toward the future.

"The wheels are always turning [in Brooks' mind] ... I think he's always thinking about what's ahead," Kennedy says of Brooks. "I don't know where we're gonna play next, but it's probably already on his refrigerator."

It's that "anything goes" spirit with which Brooks approached his turn as Gaines that keeps Kennedy coming back for more. "Any time he calls and says, 'Hey, do you want to --' 'Yeah.' Without question. Because it's gonna be an adventure," the songwriter says. It's how Kennedy recently wound up getting SCUBA certified so he could spend hours underwater filming Brooks' forthcoming "Dive Bar" music video.

"When we were in the studio [for the Gaines album], we would start at noon every day and finish at about 4 or 5 in the morning, but we knew we were doing something, to say the least, unique," Kennedy says. "It's one of the reasons why I keep answering the bell anytime he wants me to do something.

"Just the experience of that was phenomenal."

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