Tennessee Ernie Ford - Blackberry Boogie (c.1952)
…it’s a Tennessee Ernie Ford kinda day
Tennessee Ernie Ford - Sixteen Tons

The Tennessee Ernie Ford version of this song was played over the closing credits of the “Seven Twenty Three” episode of Mad Men (Season 3, Episode 7), in which Don Draper begrudgingly signs a three-year employment contract with Sterling Cooper.
Listen to a great, bluesy version of Sixteen Tons by Lipbone Redding HERE