It seems like country music has been considerably influenced by The King, Elvis Presley, that is.
And I would argue that there's more King of Rock influence in today's country than the King of Country, Roy Acuff. I wish we could hear Acuff's influence a little more in modern country artists. Not only was Acuff an excellent singer, he was a class act and set the standard as country music's ambassador for the better part of six decades.
Here's a live version of Acuff performing his signature song, "Wabash Cannonball" on the Grand Ole Opry.