Determining the first actual rock & roll record is a truly impossible task. But you can't go too far wrong citing Jackie Brenston's 1951 Chess waxing of "Rocket 88." (AllMusic) On that basis, Significant, though the man himself remains Obscure outside the cognoscenti. File under: Pioneers and Progenitors.
Discography:
In the music library: Bob Dylan's Theme Time Radio Hour: The Best Of The Third Series: Much Later
The Sound Of The City - Memphis: Rocket 88 (Jackie Benston and his Delta Cats)
Links: Wikipedia AllMusic Discogs 45cat All About Blues Music The Mississippi Blues Trail