The Beatles met Elvis Presley only once, at his home in Los Angeles while they were on their second US Tour in August 1965.

"It was just like a dream, really, meeting Elvis. We'd fantasized about him since we were kind of young teenagers and here he was in the flesh. So it was great. It was lovely," says McCartney.

They talked and played Elvis's guitars. But McCartney says it was the King's TV he remembers best.

"I think the most amazing thing besides actually just meeting him was he had the first remote television channel changer that we'd ever seen, 'cause you know, it was that year when they came out," McCartney remembers.

"He was just aiming it at the TV, and the channels were changing and we go 'Whoa! He is indeed the mighty God. He can turn the channels without approaching the television set!' So we were very impressed by that."

In fact, the first wireless remote, Zenith's Flashmatic, was released ten years earlier, in 1955. It controlled sound and channels by flashing a beam of light at the television. The only problem? On nice days, sunlight would sometimes change the channel on you.

But remotes were slow to take off. In 1961, when they had switched from light to ultrasound to control televisions, people were still pretty impressed by the technology, as is evidenced by an exuberant RCA commercial that WIRED wrote about in 2013. And even by 1979, only 17 percent of homes in the US had remote controls for their televisions.

So for McCartney, the clicker was a revelation. And speaking of clicking, he says the Beatles didn't use click tracks, either.

"Drummers notoriously speed up. I don't really think Ringo ever did—he held a really good tempo—but if he did, we'd just go with him," he says. "He was a great drummer so we didn't need a click track. Also, we didn't have one even if we had needed one."

Hear much more from Sir Paul, including what he remembers about being knighted, in the video above.

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