Johnny Cash Sings about the Hows and Whys of Gun Violence

In my criminology classes, I sometimes use music to illustrate theoretical points.  There is the “ecologica” theory school of thought which means that when you mix too many volatile elements together, you get trouble.  E.g. mix young males, alcohol, and guns together and you are more likely to get violence.  Close the bar, keep  the kids out, or control the guns and you get less trouble.  Some pointy headed academics came up with this idea in the 1980s, but Johnny Cash was already singing about it in the 1950s.