During the Season 23 finale of 'American Idol,' Carrie Underwood performed 'I'm Gonna Love You' with finalist Slater Nalley, and Cody Johnson joined in as a surprise star guest.

Carrie Underwood gave fans a blast from the past by performing "Alone" on "American Idol," two decades after doing so on the show in 2005. Watch Party Newsletter What to watch Win $100 💵📚 ...