I hadn’t actually met Elvis before I went to work with him,” says the legendary guitarist James Burton, who’d already worked with a veritable who’s who of rock stars when he picked up the phone one night in 1969 and found himself speaking to the King himself, Elvis Presley. “I’d played the Louisiana Hayride around the time he came through, when he was just starting out, but I didn’t actually meet Elvis until 1969. He called me on the phone at my home in L.A., and I talked to him for two or three hours on the phone. He asked me if I’d be interested in going to Vegas and putting a band together for him. So I did.”

Burton may seem matter-of-fact about the call, which began a creative partnership that lasted until Presley’s death in 1977, 42 years ago this week, but that band, and the shows at Las Vegas’ International Hotel, now immortalized on an 11-CD box set featuring 11 complete concerts, as well as a two-LP set featuring the incendiary opening-night performance, catapulted Presley, whose career had fallen dormant after a stint in the army and a series of increasingly awful films, back into the pop culture firmament on the heels of his 1968 NBC television special.

“We talked about everything,” Burton recalls of that first conversation with Presley. “Mainly, we talked about the Ozzie and Harriet TV show, because he remembered watching me play guitar alongside Ricky Nelson which, I have to admit, I thought was pretty cool. But then he said that when he told the people around him that he was getting ready to make some changes—to do some live shows and hopefully make some records—that everybody he had talked to mentioned me, and said, ‘You should call James.’”

As excited as he was by the opportunity, Burton still chuckles at the memory.

“I was late for my recording session that day and I kept telling Elvis, ‘I’ve gotta go to work,’” Burton says with a laugh. “But he just kept going on. It was like we knew each other already through the music we both liked, which was pretty much the same: gospel, country, then rock and roll, but also bluegrass, folk music and everything else.”

Soon, Burton was lining up players for Presley’s band and putting them through their paces, in anticipation of their first rehearsal for Presley’s triumphant return to live performance at the International Hotel on July 31, 1969.

“Of course, the band I put together was a killer band,” Burton recalls, in a massive understatement.

He tapped John Wilkinson on rhythm guitar, Larry Muhoberac for keyboard duties and the men who became fan favorites for the monstrous grooves they supplied behind the King: Ronnie Tutt on drums and Jerry Scheff on bass.

These were experienced hands—players Burton knew could handle the gig musically, but who could also approach playing with the most famous performer in the world with their feet on the ground.

“It was plenty exciting when Elvis first arrived at rehearsals,” Burton recalls. “But as famous as he was, when we met and shook hands with each other, it was like we’d known each other our whole lives, because the style I played was kind of a mixture of the same influences he was using as a singer. It was unbelievable, because I knew I blew him away, and the band just blew him away, too. He loved it.”

With those initial rehearsals under their collective belts, Presley’s stint in Las Vegas was next.

While there have been plenty of releases chronicling Presley’s Vegas years, which ran almost until his death—and are often cited as one of the key factors in what made Sin City a destination for so many vacationers—all of them, including the excellent Live in Las Vegas box set and the expanded edition of the film That’s The Way It Is, chronicle a leonine and confident Presley and company loose, but also performing a well-rehearsed and supremely self-assured show.

Live 1969, on the other hand, offers fans the origin story.

“Elvis was really nervous,” Burton recalls of the opening night, which also happened to be Burton’s birthday. “He said to me, just before we went on, ‘James, I don’t think I can go on.’ It kind of shocked me. He was Elvis Presley, after all. But he did go on, and he just killed it.”

From the opening notes of Presley’s 1950s hit “Blue Suede Shoes,” re-imagined for the Vegas stage, there’s an electricity present that is somehow different than even the best Presley performances. Along the way, Presley misses cues, stutters during some of the introductions, and jokes that he’ll get the hook, even after 14 years on top, if he doesn’t please his bosses at the International. These moments humanize Presley while lending a sense of urgency to the proceedings remarkably different to the oft-excellent but supremely choreographed shows Presley would turn in over the next eight years.

Burton was with him through it all, but recalls those early Vegas shows as special.

“I did everything from ‘69 up until he died,” Burton says, a hint of sadness in his voice. “We did all the Vegas runs. Aloha From Hawaii. We also did all of Elvis’ recordings. But those early Vegas shows were the most special of all, looking back.”

Elvis would only do maybe three or four takes, at the most. His feeling was that if it didn’t happen, if it didn’t come together within three or four takes, it was time to go on to something else.

Also out later this month is American Sound 1969, showcasing Presley’s studio sessions from that year, which yielded the hits “In the Ghetto,” and, of course, “Suspicious Minds,” as well as Presley’s take on The Beatles’ recent smash “Hey Jude,” the R&B groove “Rubberneckin’,” and the epic “Kentucky Rain.”

“It didn’t matter what song it was,” Burton, who joined up with Presley too late to take part on the 1969 Memphis sessions, but who worked with him in the studio on nearly every session after that first Vegas run, recalls. “Elvis would only do maybe three or four takes, at the most. His feeling was that if it didn’t happen, if it didn’t come together within three or four takes, it was time to go on to something else.”

Far from the spent creative force much of the public perceived Presley to be at the dawn of the 1970s, with Jimi Hendrix, The Who and the Doors topping the charts worldwide, Presley sounds as intense and confident as ever on American Sound 1969.

“Elvis was a really hard worker in the studio,” Burton says, smiling at his memories of working with Presley on his recording sessions. “He really got down to business. It was amazing. When the red light came on he would just go for it.”

Presley, Burton says, also had his own quirks and unique ways of doing things, much to the chagrin of some of the producers and engineers he worked with.

“Elvis used his own mic,” Burton says. “He had a mic that had his name on it that he used for live shows, and for recordings as well. It was just a handheld mic. Producers would try to convince him to use different mics—better mics—but he always went back to his own mic. And he liked to have the singers and band close by so we could have eye contact, and so he could get into a good groove. So it was always a performance in the truest sense, and he was acting as both performer and producer. He’d have a producer, but the bottom line was that Elvis had the final say if it was something he liked or disliked.”

Of course, after the stint in Vegas, Burton’s hand-chosen TCB Band—named by Presley for Taking Care of Business—was at Presley’s beck and call.

“When I went to work with Elvis, I became family,” Burton says. “That’s how it felt, and that’s what he wanted. That’s the way he liked it. That made the hours and demands feel like nothing at all.”

“He loved guitar. When I’d play a hot lick or something, he’d turn around and say, ‘Yeah baby, yeah! That’s it!’ You can hear it on the records, but really see it in the films of us. We had this great communication on stage. And that feedback was indescribable. But he wanted you to feel good and happy. He wanted everything to be just right. That’s the way he was. And most of all, he wanted to hear the truth.”

Even 50 years after their first meeting, and more than 40 years after Presley’s untimely death in 1977, Burton speaks in the present tense about his former boss. But as we wrap up, he reflects on the King as so few knew him.

“I still think about what a great guy he was,” Burton says of his memories of the man the rest of us have only ever known from afar. “He was an incredible person to work with, and was always concerned if you were happy or if everything was OK. And if something wasn’t right, he would make it right. That’s how I remember him, and it’s a great memory, I think.”