Carrie Underwood refuses to perform emotional track

Country star Carrie Underwood will never perform one of the songs from her new album live as the lyrics remind her of her late grandmother.

The singer's latest record, Blown Away, includes a track called Forever Changed, about a woman who mistakes her son for her husband.

Underwood reveals one of the writers was inspired by his mother's battle with Alzheimer's disease but the words make her think of her late grandmother and she can't bring herself to perform the haunting track.

She tells ABC's Nightline, "I get emotional even talking about this song to be honest. It's just beautiful. It just becomes very real... and I remember my grandmother at the end of her life, looking at my dad and thinking that that was my grandfather.

"I can never sing this song, like on stage in front of people. I could barely get through it in the studio."