Country music’s legendary rhinestone cowboy, Glen Campbell, is taking his last bow this fall. The 78-year-old, who was diagnosed with Alzheimer’s disease in 2011, said farewell to fans on a Goodbye Tour in 2012, but this week marked the official sunset of Campbell’s professional music career. The week before the release of the documentary Glen Campbell: I’ll Be Me, the Country Music Hall of Fame member released his final single, a heartbreaking ballad called I’m Not Gonna Miss You, which was recorded in early 2013 for the film.

The song doesn’t mince words as it reflects on the degenerative destruction of Alzheimer’s: “I’m still here, but yet I’m gone/I don’t play guitar or sing my songs,” Campbell groans in the opening stanza. But the track is more than a mournful lament – it’s a love letter to his wife of 32 years, Kimberly Woolen. Campbell muses on the chorus: “You’re the last person I will love/You’re the last face I will recall/Best of all, I’m not gonna miss you.” It’s a harrowing and romantic sentiment, and one that feels well-suited to a country song.

Country music’s ageing royalty have been willing to stare death directly in the face – and sing about it. In the years before he died in 2003, Johnny Cash frequently reflected on his own mortality – first on his profoundly effective cover of Nine Inch Nails’ Hurt, in which he rejected his life’s “empire of dirt”, and later on his final album with The Man Comes Around, a song that references the end of the world as described in Revelation. Dolly Parton hasn’t shied away from such content either, though she takes a far more winsome approach than Cash. Her 2005 duet with Brad Paisley, When I Get Where I’m Going, imagines the “happy tears” she’ll cry in heaven, and her criminally overlooked 2013 duet with Kenny Rogers, You Can’t Make Old Friends, considers the value of lifelong friendships and the pre-emptive sadness that old age may end them soon. Willie Nelson’s recent reflection on death is blunt too, though in keeping with his persona. In 2012 he released a single called Roll Me Up and Smoke Me When I Die.

Songs like these and Campbell’s I’m Not Gonna Miss You aren’t eulogies in the same vein as Elton John’s Candle in the Wind, written in honour of Marilyn Monroe, or Eric Clapton’s Tears in Heaven, written after the death of his four-year-old son. They’re personal songs about dying, not death, that demonstrate a simultaneous fear and acceptance of the human condition. In this way, they resemble (lyrically if not sonically) Queen’s anthemic The Show Must Go On, which detailed Freddie Mercury’s battle to keep performing despite suffering with Aids.

Country music is well-suited to produce such serious fare, as the genre has traditionally been willing to listen to the wisdom of its elders over the noise of club beats. Pop’s ageing stars have always had to prove their appeal to younger generations (it’s no surprise that Tony Bennett and Barbra Streisand’s new albums feature duets with Lady Gaga and John Mayer respectively), but country artists have typically been freer to wear their wrinkles and let their music communicate their weathered perspectives about death, or friendship, or marijuana, or even Alzheimer’s.

Current mainstream country music, though, has emphatically ejected its older stars from the larger conversation. Florida Georgia Line may name-drop Merle Haggard in every other song, but the duo’s music suggests that they’re far more concerned with rhyming “party” and “Bacardi” than they are with learning about the deep roots of Nashville tradition. Jason Aldean may claim to listen to George Jones, but his music imitates hip-hop and pop more than any classic country songs. (Aldean’s current single, Burnin’ It Down was, after all, co-written by the members of Florida Georgia Line.) Country radio has so zeroed in on the young, male, tailgating demographic that Clear Channel has recently launched Nash Icons, a brand of stations promising to play older artists, to restore balance to the airwaves. The reality is that in 2014, while Glen Campbell grapples with forgetting, his peers must grapple with being forgotten.

Perhaps it’s this death in the mainstream imagination, that has older country stars considering their ultimate ends and recording music so unabashedly uncommercial. And perhaps it’s this estrangement from the music industry, when coupled with the reality of growing old, that has them crafting such bracingly honest and gloriously nuanced art. Campbell’s I’m Not Gonna Miss You music video has been viewed nearly 2m times in the past week – not because it’s a broadly consumable party jam, and not because Campbell is in his prime, but because the song’s content feels so unflinchingly real that it automatically stands out among all the posturing plaguing modern country.