This was Presley’s first commercial recording for Sun Records. Sam Phillips matched Presley with Scotty Moore and Bill Black, and Phillips had the three rehearse several songs, trying to find the sound Phillips was after. They found it in an obscure 1946 blues song by Arthur “Big Boy” Crudup called “That’s All Right”. By changing the tempo to upbeat blues, some music historians now consider it the first song of the rock and roll genre.