John Mayall and the Bluesbreakers' rocking 1966 cover of Ray Charles' "What'd I Say" features a very young Eric Clapton on lead guitar.
However, to put it bluntly, even though it appears on a legendary guitar album—Blues Breakers with Eric Clapton—"What'd I Say" is not a standout track by any means. It just sort of sits there, and its lengthy (and weird) drum solo by Hughie Flint isn't exactly "Moby Dick." Who knows—maybe it was a crowd favorite at the Bluesbreakers' live shows.
Anyway, there is this oddity to consider: When the rest of the band comes back into the song after Flint's drum solo (at 3:36 in the top video), Clapton is playing the very-hard-to-miss guitar riff from the Beatles' late-1965 single "Day Tripper"—over and over again. Blues Breakers was recorded in March 1966, so there's no question as to "whose riff it was."
Plagiarism? Maybe by today's litigation-happy standards. But in reality, it's just a 21-year-old (almost 22-year-old) guitarist being irreverent and having fun, quoting a famous song within another song, just as he did when he quoted the melody to Rodgers & Hart's "Blue Moon" in the guitar solo to Cream's "Sunshine of Your Love" a year later (skip to 2:04 in the bottom video).
As a member of a cover band, I can tell you it's fun—and often funny—to insert the "Day Tripper" riff wherever it fits, which is almost any classic rock or upbeat blues song in E major.
Clapton had already met the Beatles at this point (they first met in December 1964 when Clapton was in the Yardbirds), and his decades-long friendship with the Beatles' George Harrison was in its very early stages. Let's consider this little "What'd I Say"/"Day Tripper" episode the first recorded connection between Clapton and the Beatles.
Clapton's "Day Tripper" riff starts at 3:36 in the top video.
Damian Fanelli is the online managing editor at Guitar World and Guitar Aficionado. His New York-based band, the Blue Meanies, has toured the world and elsewhere. Fanelli, a former member of Brooklyn jump-blues/swing/rockabilly band the Gas House Gorillas and New York City instrumental surf-rock band Mister Neutron, also composes and records film soundtracks. He writes GuitarWorld.com's The Next Bend column, which is dedicated to B-bender guitars and guitarists. His latest liner notes can be found in Sony/Legacy's Stevie Ray Vaughan: The Complete Epic Recordings Collection. Follow him on Facebook,Twitter and/or Instagram.