Here we have another perceived bad boy who spent a period of their life following all the rules. One of the most famous musicians in the world, Johnny Cash wasn't always so well known. Before he hit the big time, Cash was just a regular guy enlisting in the United States Air Force in 1950. As far as military roles go, Cash had a pretty cool job in Germany as a Morse Code operator.
After more than three years of service, where he spent most of his time intercepting Soviet Union communications, Cash was granted an honorable discharge. He went on to become one of the bestselling artists of all time, with 90 million album sales worldwide. Like John Coltrane, Cash developed his musical talent further while serving in the military, creating his first band, The Landsberg Barbarians.