The Band Perry's harmony-driven, banjo-laden rendition of "Gentle on My Mind" is featured on the soundtrack to the documentary, "Glen Campbell: I'll Be Me," and was one of the highlights of both the 2013 Grammys and 2014 CMA Awards. The documentary, which premiered Oct. 19 at the CMA Theater in Nashville's Music City Center, details Campbell's battle against Alzheimer's disease and the effect that it has had on his family.

Campbell announced his diagnosis of Alzheimer's disease in 2011. The singer, 78, was moved to a Nashville Alzheimer's care facility in April.

This week, The Band Perry released an official music video for their version of "Gentle on My Mind." The clip blends footage of the group performing with picturesque acting scenes shot in Death Valley, Calif. The actors play out the song's storyline of a young man overcome by wanderlust who chooses to leave his love for a ramble through the desert - but he can't get her out of his head.

"Gentle on My Mind" won four trophies at the 1968 Grammy Awards - two for Campbell and two for its writer and original performer, John Hartford. Literally hundreds of artists, from Frank Sinatra to R.E.M., have covered the song since, but the Band Perry is the only act to get a Grammy nod for doing so, reports Rolling Stone. They're up for Best Duo/Group Performance at February's event.

Campbell is also nominated for Grammys for "I'm Not Gonna Miss You," the final song he recorded before retiring. It's in both the Best Country Song and Best Song Written for Visual Media categories.

"What a beautiful lyric," Kimberly Perry told the Tennessean about "Gentle On My Mind." "Every time we're singing it in our three-part family harmony it feels like we're are singing a poem. It's one of the most beautiful lyrics to ever come out of this format, and it's truly an honor to honor Glen with this song."

Campbell is best known for his hits that include "Gentle on My Mind," "Wichita Lineman," "By the Time I Get to Phoenix" and "Rhinestone Cowboy." He is a member of the Country Music Hall of Fame and the Grammy Hall of Fame. He also was the host of "The Glen Campbell Goodtime Hour," a popular television show in the late 1960s and 1970s, and as a studio musician played on some of the biggest pop and rock hits of the 1960s.

Check out the "Gentle On My Mind" video by The Band Perry here: