The singer stepped in on behalf of the ailing country music icon at the awards ceremony Sunday night

By Jacqueline Andriakos
Updated February 22, 2015 05:00 PM

There was not a dry eye in the room during Tim McGraw‘s Oscar rendition of “I’m Not Gonna Miss You.”

The country star took the stage Sunday night in a cowboy hat and TK, stepping in for Best Original Song nominee’s original performer and writer, Glen Campbell. The slow acoustic track is part of the documentary Glen Campbell I’ll Be Me, which follows the singer-songwriter through his last tour and ongoing battle with Alzheimer’s disease.

The country icon, 71, was too sick to attend the awards ceremony due to his deteriorating health. He was diagnosed in 2011 and now lives in a care facility in Nashville.

McGraw preceded his performance with sentimental remarks that left the audience, including Campbell’s wife and children, in tears. “QuoteTK,” he said, thanking Campbell for inspiring him as an artist and TKTKTK.

McGraw s emotional coverage of the song had a similar effect on onlookers Friday night during rehearsals.

People watching the rehearsal were spotted wiping tears from their eyes, USA Today reported. “I’m proud to be a part of this,” McGraw said at the mic.

Campbell penned the Grammy-winning song with Julian Raymond.

The 2015 Oscars, hosted by Neil Patrick Harris from the Dolby Theatre at the Hollywood & Highland Center in Los Angeles, are airing live on ABC.