It reached number 8 on the Billboard Country charts in 1959, but this is the kind of song that crosses genres.  By the late 1950s rock & roll was the most controversial and dominant musical force in America, but there were still plenty of artists who could comfortably fit into country and rhythm & blues as well as rock charts.  Johnny Cash was a performer who defied genre and expectation.

When Luther played that boogie woogie, the crowd ate it up!

We were just a plain ol’ hillbilly band with a plain ol’ country style
We never played the kind of songs that’d drive anybody wild
Played a railroad song with a stomping beat
We played a blues song, kinda slow and sweet
But the thing that knocked them off of their feet was, ooh-wee

Sounds to me like they added a little rock & roll.  Luther played it…