This was originally recorded in a blues style by Big Mama Thornton in 1953. Her version was a #1 R&B hit and by far her biggest success. Like many blues musicians, she never made much money, but was a big influence on many singers who did. In 1968, Janis Joplin recorded a song Thornton wrote called "Ball and Chain," which appeared on several Joplin compilation albums after she died in 1970.
Elvis' version of this song is based on how he heard it performed by a Texas group called Freddie Bell and The Bell Boys, who released the song on the Teen label in 1955. In April 1956, Elvis was booked for two weeks at The New Frontier Hotel in Las Vegas. One night, Elvis and his band explored the Vegas strip and landed at the Sahara, where Freddie Bell and The Bell Boys were performing in the lounge. When they performed their comedic version of "Hound Dog," Elvis was impressed and decided to do his own in a similar vein.
Elvis used the same lyrics, which differed from the Big Mama Thornton original. In this approach to the song, Elvis is acting disappointed with his lover and repeating the lyrics, "Well, they said you was high-classed, but that was just a lie" six times. In Thornton's original, she sings the line twice as "You told me you was high class, but I can see through that."
This was one of the first big hits for the songwriting team of Jerry Leiber and Mike Stoller, who were teenagers when they wrote it. Based on the success of "Hound Dog," Leiber and Stoller were hired to write many more songs for Elvis, as well as the score for his movie Jailhouse Rock (including the famous title song).