Tim McGraw took to the stage of the Kodak Theater Sunday night to sing Glen Campbell‘s Oscar-nominated song “I’m Not Gonna Miss You.”

Tim McGraw’s Oscar Performance

McGraw kept things focused on the music while performing the song Campbell wrote with Julian Raymond as a love letter to his family for his 2014 documentary, Glen Campbell… I’ll Be Me. The country music star, dressed in a black tuxedo and sporting his signature black cowboy hat, left his guitar behind to sit on a stool and deliver a moving performance of “I’m Not Gonna Miss You.”

McGraw was stepping in for Campbell at the awards show because the music icon, who was diagnosed with Alzheimer’s in 2012, has seen his health decline considerably in recent months.

Campbell’s longtime producer and co-writer Raymond acknowledged that Campbell, due to his dementia, doesn’t understand that his final song received a nod from the Academy. However, Raymond finds solace in that Campbell was honored with a Lifetime Achievement award at the Grammys before the disease took over.

“I was so pleased that the Grammys gave him a Lifetime Achievement award when he could still understand what it was and appreciate it. But this is a whole different deal,” Raymond said. “It’s a cliché thing to say, but I’m just so happy to be nominated, for him and his family. I feel just so happy that this whole thing is creating a brand-new legacy for him and getting some of those great old songs heard. As we joke, he’s lived a thousand lifetimes. He’s just amazing in so many ways.”

“I’m Not Going to Miss You” lost out to John Legend and Common‘s song “Glory” from Selma. Songs from The Lego Movie, Beyond the Lights and Begin Again were also nominated.