4. "Mammas Don't Let Your Babies Grow Up to Be Cowboys"
If anyone was qualified to warn expectant mothers against the dangers of the rock & roll lifestyle, it was Waylon Jennings, who started making his living as a hard-living cosmic cowboy in the late 1950s. To strengthen the message, he teamed up with Willie Nelson to record this cautionary classic in 1978. Ed Bruce, the song's original writer, cracked the Top 20 in 1976 with his own version, but it was Jennings and Nelson's rendition that turned "Mammas" into a staple of outlaw-era country, leaving such a long, multi-faceted legacy that everyone from Black Lips to Alvin & the Chipmunks has since attempted to cover it. Oddly enough, Waylon's wife — fellow country rebel Jessi Colter — didn't take her husband's advice, leaving the couple's only son, Shooter Jennings, to launch his own career as a country singer two decades later. Whoops.