A stinging Chuck Berry-esque guitar opener leading into a shoulder-shrugging rock strut, while the chorus sings at some bleary distance, as if they wandered into the adjacent recording studio and were too stoned to find their way back out.

A lost track from Exile on Main Street, you guess? Nah; it’s early B.B. King, from the mid-to-late 50s, performing a track by one of his influences, the great jump blues singer Louis Jordan.

King is of course a blues performer, but listening to his early work you’re reminded that the line between early rock and early blues basically didn’t exist.

Check out the raw rave up of “Shake It Up and Go” from 1952; harsh, driving, raucous rock and roll two years before Elvis was supposed to have invented it, with King’s stinging guitar lines presaging—well, basically everything.

King had become an institution before his death, but there’s nothing of the institution about this track’s hip, microphone-bruising strut. This right here — jump blues wedded to electric guitar, with nonsense lyrics (“Mama killed a chicken/she thought it was a duck”), recorded loud enough so that the amp sounds like it’s going to expire — this, B.B. King is telling you, with cheerfully brutal conviction, is going to take over the world.

And so it did. Which is why King today is name-checked by just about every rock performer who’s picked up an ax— Eric Clapton, Keith Richards and Jimi Hendrix are the stars most often linked to him, but Billy Gibbons, Joe Perry and a host of others have lined up to pay tribute as well.

Rock musicians love the King of the Blues—almost as if blues and rock, so intimately tied together in the 50s, never really did separate after all. Why are Eric Clapton and ZZ Top rock, anyway, if B.B. King is the blues? When Valerie June or Trampled Under Foot lean into one of those B.B. influenced solos, are they performing retro-blues or retro-rock? How can you tell?

Valerie June

Trampled Under Foot

All of which makes you wonder: if B.B. King performed music indistinguishable from rock in the 1950s; if he made music much like rock musicians of the 60s and 70s; if his influence now can’t really be distinguished from that of the rock musicians who followed him—why exactly is he King of the blues, and the blues only? Why is his influence on rock only an influence? Why isn’t he the King of Rock?

Of course, he’s not the King of Rock because the King of Rock is that guy with the hips who came along a couple years after “Shake It Up and Go.” Elvis had his own, jittery imitation of King and all the other jump blues and blues and R&B artists who had, together, and with some help from country musicians, put together the elements of the genre we know as rock.

Rock was multiracial music; King himself drew on Django Reinhardt as well as Louis Jordan. But the complicated strands of mutual influence over time got flattened out in the popular consciousness, and what was left was that iconic performer: the King, who was a white man playing music associated with black people.

And over time, that’s the definition of “rock” that won out: black music played by white performers. The genre boundaries were never completely solid, of course—there was enough give that a Jimi Hendrix could slip through by playing psychedlia with white guys. But for the most part, as Dee of fyeahblackrockmusic often points out, black performers who played rock, like Ray Charles, or Otis Redding, or Etta James, or Motown, weren’t allowed to be rock. Instead they got classified as R&B or blues.

And so B.B. King, an innovator who synthesized music from disparate performers, became an influence—someone mainstream artists drew on to show their cred, rather than part of the mainstream himself. He’s the tradition that geniuses riff upon; a blueprint from which innovators build their canonical Exile on Main Streets or their Laylas.

Authenticity is bestowed on black musicians like a laurel, but it’s often also a cage. As a roots musician, King’s vitality and energy are figured as always already buried, waiting for someone to draw it out. Whereas the Rolling Stones can be the swaggering young ever-relevant bad boys even on their umpty-umpth geriatric tour—even if they never really recorded anything that grabbed onto the future and howled the way that “Shake It Up and Go” did.

As the tributes to him show, King was widely admired and venerated; he enjoyed his place in the blues and his mastery of it. He didn’t seem to need or want more accolades than he had; he didn’t, for himself, need to be the King of Rock.

That doesn’t change the fact that he has at least as much right to that title as Elvis, who was, for all his popularity, less innovative, less consistent and less influential. Taking a moment to remember B.B. King as the King, period, no “of” needed, is more for our benefit than his. It’s a reminder of what we miss when we put genius in a box made out of genre, or in one made out of race.

Noah Berlatsky edits the comics and culture site the Hooded Utilitarian and is a contributing writer for The Atlantic.