For as much as Twitty is one of country's greatest and most successful artists of all time, it's often overlooked that he started out in pop and rock & roll. After a short stint with Sun Records when he wrote the Roy Orbison hit "Rock House," Twitty moved to MGM and released the 1958 Number One "It's Only Make Believe," which featured backing vocals from the Jordanaires. He followed that with rockabilly-flavored singles like "Danny Boy" and "Lonely Blue Boy" but moved to country in the early Sixties when his rock singles stopped charting. From there, of course, he went on to accumulate the most country Number Ones in history until George Strait eventually eclipsed him. More importantly, he brought a sensuality and sexuality to country music that can still be heard in the work of everyone from Blake Shelton to Sam Hunt. — J.F.