Watch Tim McGraw Perform at the 2015 Oscars!

Tim McGraw paid homage to one of his forbears at the Oscars, performing a moving tribute to Glen Campbell.

The documentary Glen Campbell: I’ll Be Me follows the farewell tour of Campbell, a famed country performer (known for his rendition of “By the Time I Get to Phoenix”) who’s leaving the spotlight after an Alzheimer’s diagnosis. Its Oscar-nominated theme song “I’m Not Gonna Miss You,” performed by McGraw during the Oscars telecast, was co-written by Campbell.

“It’s not gonna hurt me when you cry,” McGraw sang, a heart-breaking line eluding to the effects of Campbell’s disease.

McGraw was handpicked by the Campbell family to fill in for the ailing legend. A first-time Oscar nominee, Campbell was unable to travel to Los Angeles for the show due to his deteriorating health.

See Glenn Campbell sing it below: