The first band to be regarded as TRUE jump was Louis Jordan and the Tympany Five. And the first song to be regard as TRUE jump was their 1946 number entitled "Choo Choo Ch' Boogie." The argument that rock 'n' roll can be regarded as that point where blacks and whites mixed styles whether intentionally or otherwise has some merit. "Choo Choo Ch' Boogie" was written by three white "hillbilly" writers--Vaughan Horton, Denver Darling and Milt Gabler. The label was Decca (American Decca, that is) which deserves a lot of credit in pioneering rock 'n' roll. Eight years later, Milt Gabler would produce the Comets' "Rock around the Clock" for Decca.
Louis Jordan Singalong Choo Choo Ch'Boogie - YouTube
Another big jump number from Louis Jordan was 1949's "Saturday Night Fish Fry":
Saturday Night Fish Fry Louis Jordan - YouTube
Detroiter Wild Bill Moore recorded "We're Gonna Rock, We're Gonna Roll" in 1948:
We're Gonna Rock by Wild Bill Moore (1948) - YouTube
The very title qualifies it as a true rock 'n' roll number. But is it the first? And if this is not rock 'n' roll then is it by coincidence that we hear Wild Bill Moore's sax on Marvin Gaye's "Mercy Mercy Me"?
On Moore's recording, Paul Williams plays the baritone sax. Williams came out of a hard-driving R&B Detroit outfit run by King Porter. He went off on his own and while touring with Lucky Millinder, heard their reworking of a Charlie Parker's 1945 bop number "Now's the Time":
Charlie Parker - Now's The Time - YouTube
Millinder's band reworked the number into a blues format:
Lucky Millinder & His Orchestra - D' Natural - YouTube
When Williams heard the song, he thought it would go well with a new dance he'd seen being done in the clubs. When he asked people what it was called, they said, "The hucklebuck!" although it has alternate pronunciations as huckabuck and huckerbuck. Williams recorded Millender's number under the title of "Hucklebuck" in 1949 o the Savoy label while in New York producing a million-seller that he lived off for the next ten years. Williams is, in fact, generally known as Paul Hucklebuck Williams. This is very often called the very first rock 'n' roll song. While I would argue that, I will not argue that it demonstrates the importance of bop to the formation of rock 'n' roll.
Paul Williams - The Humblebuck - YouTube
The Hucklebuck become famous enough that established artists as Sinatra and Connie Francis cut their own vocal versions.