Arthur William “Big Boy” Crudup (August 24, 1905 – March 28, 1974) was an American Delta blues singer, songwriter and guitarist. He is best known, outside blues circles, for his songs “That’s All Right” (1946), “My Baby Left Me” and “So Glad You’re Mine”, later recorded by Elvis Presleyand other artists.

Crudup was born in Forest, Mississippi, to a family of migrant workers traveling through the South and Midwest. The family returned to Mississippi in 1926, where he sang gospel music. He had lessons with a local bluesman, whose name was Papa Harvey, and later he was able to play in dance halls and cafes around Forest. Around 1940 he went to Chicago. He began his career as a blues singer around Clarksdale, Mississippi. As a member of the Harmonizing Four, he visited Chicago in 1939. He stayed in Chicago to work as a solo musician but barely made a living as a street singer. The record producer Lester Melrose allegedly found him while Crudup was living in a packing crate, introduced him to Tampa Red and signed him to a recording contract with RCA Victor‘s Bluebird label. He recorded with RCA in the late 1940s and with Ace Records, Checker Records and Trumpet Records in the early 1950s. He toured black clubs in the South, sometimes playing with Sonny Boy Williamson II and Elmore James.^[4] He also recorded under the names Elmer James and Percy Lee Crudup. His songs “Mean Old ‘Frisco Blues”, “Who’s Been Foolin’ You” and “That’s All Right” were popular in the South.^[5] These and his other songs “Rock Me Mama”, “So Glad You’re Mine”, and “My Baby Left Me” have been recorded by many artists, including Elvis Presley, Slade, Elton John and Rod Stewart.