He began his career with fellow Texan, Buddy Holly as a member of his band The Crickets. Glen Hardin would become Elvis Presley's piano player for many years, play in John Denver's band, as well as doing studio work for such luminaries as Frank Sinatra and Bing Crosby.
During his long career, the highly versatile musician has played on recordings for numerous singers in a variety of music genres including: Emmylou Harris, Dean Martin, Ricky Nelson, Buck Owens, Linda Ronstadt, Kenny Rogers, Johnny Rivers, Merle Haggard, Michael Nesmith, Waylon Jennings, and Dwight Yoakam. He also played piano on the highly acclaimed Roy Orbison television special, A Black and White Night.