Okay, everybody hang on.
Count Basie is NOT “easy listening.” His 1930s band exemplified the hard-swinging Kansas City blues style that cradled Charlie Parker and led directly (through '40s style R&B) to rock and roll.
You don’t believe it, listen to the landmark late-‘30s Decca recordings. Or especially Count Basie, Lester Young and the Stars of Birdland Live at the Municipal Auditorium, Topeka Kansas, February 1955 (Jass Records, J-CD-17). "Jumpin’ at the Woodside" ROCKS. And when Joe Williams steps up to the microphone and they swing into “Every Day I Have the Blues,” they rock HARDER.
Please do not conflate jazz artists with “easy listening” people…Ray Anthony. Any of that “Music for Lovers” Jackie Gleason stuff. Ray Conniff. Hugo Winterhalter.
Nat King Cole with strings is “easy listening.” Nat King Cole with his trio in the 1940s is jazz. Nat King Cole with Lester Young and Buddy Rich is jazz. Nat King Cole singing “Route 66” with Harry “Sweets” Edison backing him on trumpet is jazz.
Mel Torme with strings is “easy listening.” Mel Torme with the Marty Paitch Dek-tette is jazz.
Early Bing Crosby is jazz. Late Bing Crosby is “easy listening.”
I think it’s a matter of intent. Fred Astaire, to my mind, was one of the great popular singers…Irving Berlin said he always imagined Fred singing his tunes as he was composing. But when Fred sat down with Barney Kessel and Flip Phillips and Oscar Peterson in the early '50s and made The Fred Astaire Story, he turned his brilliant sense of timing and rhythm to something different that just making pretty records. He was making JAZZ.