While messing about, Elvis broke into Arthur Crudup’s R&B hit, ‘That’s All Right, Mama’. Producer Sam Phillips, who’d been scouting for just the right sound for his protege, stops everything and says, “What the hell was that?”
“We don’t know,” Elvis replied.
“Well, do it again,” insisted Sam.
The end result was Elvis’ first regional hit. Rock historians point to it as the possible birth of rock and roll music, or, at the very least, the first true merging of country, blues, and pop styles.
Elvis and his band recorded two more conventional songs that day, ‘Harbor Lights’ and ‘I Love You Because’.