Last weekend, Miranda Lambert's MuttNation benefit concert, "Music For Mutts," raised big bucks for her charitable organization, and provided fans with a night of incredible music as well. One surprise artist that appeared that night: Riley Green, who suddenly found he was free that day after Hurricane Helene came through the southeast and caused the postponement of the Field & Stream Music Festival in South Carolina, at which Green was slated to appear. South Carolina's loss was Texas' gain, as Riley showed up and performed a few of his songs for the crowd, including one of the highlights of the evening, a duet with Miranda on Riley's huge hit, "I Wish Grandpas Never Died." It wasn't originally a duet, but with Miranda and Riley together, it's hard now to hear it any other way.