Here's one for the "Bet'cha Didn't Know" file.
Before he was cast as Festus on Gunsmoke for the final 11 years of its run, Ken Curtis had already had a long, distinguished career in show business, mostly as a singer. Curtis sang with the Sons of the Pioneers, and with the Tommy Dorsey & Shep Fields bands. With Dorsey, Curtis stepped into some pretty big shoes, as he succeeded------Frank Sinatra. Talk about a tough act to follow!
Curtis came to Gunsmoke after a 2 year run on Ripcord, and created the distinctive appearance of Festus, a scruffy, illliterate sort who became more or less Matt Dillon's sidekick. After Gunsmoke ended, Curtis returned to his musical roots, taking the occasional acting job.
Following is a clip of Curtis performing a song commonly associated with the Sons of the Pioneers, "Tumbling Tumbleweeds", recorded in Germany in 1986.