Kacey Musgraves does not frequently perform duets. But for the final track on her last album, Pageant Material, she made an exception to the rule and sang with one of her genre's great ambassadors, Willie Nelson. Nelson also graciously pops up in the song's video, which came out today. The two artists sit in an empty bar while the band drifts through the tune behind them. Revisit Musgraves' cover story.