The earliest rockabilly band? That's a tough one. You would guess someone would have done sped up hillbilly with hiccupy vocals before Elvis, but who would be considered the first? The Rockabilly Hall of Fame says "Sid King and his band were often credited as being the first to create, record and play rockabilly music...the first sounds of rock and roll" citing a date of 1952. I was unable to come up with anything that sounded like rockabilly by them that was that early. (Maybe that's the reason for the "were often credited". Blame it on someone else. Good job Rockabilly Hall, it was your job to make the definitive call and you lamed out.) King and his Five Strings did get loose by 1955, that much we can ascertain.
~ NOTE: ALL MEDIA IS HOSTED BY THE BLOGS & SITES NAMED BELOW ~Listen:
Sid King and the Five Strings - Sag, Drag and Fall mp3 at Rocky 52 1955
Sid King and the Five Strings - Gonna Shake This Shack Tonight mp3 at Rocky 52 1956
Sid King and the Five Strings - Sag, Drag and Fall at YouTube