“Arthur "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 writing songs such as "That's All Right", "My Baby Left Me" and my jam for this week "So Glad You're Mine", which were all later covered by Elvis Presley and dozens of other artists.
http://en.wikipedia.org/wiki/Arthur_Crudup
Elvis Presley's cover here https://www.youtube.com/watch?v=y1iTWHRKpGc”