This emotional duet will have you hitting the play button again and again.

By Perri Ormont Blumberg
Glen Campbell and Willie Nelson
Credit: Jeff Kravitz/Getty Images

On August 8th, 2017, the Campbell family lost its patriarch, and the world at large lost an irreplaceable musical icon. As a parting gift, Glen Campbell left fans with one last studio album recorded during his battle with Alzheimer's disease: Adiós. The mellifluous medley of classic country and rock ballads includes tracks ranging from Bob Dylan to longtime collaborator, Jimmy Webb. Dear friend and producer Carl Jackson made sure the album captured the country legend's spirit in ways big and small.

Out of all the songs recorded in Campbell's final studio session, however, none tug at our heartstrings as much as much as his cover of longtime friend Willie Nelson's "Funny (How Time Slips Away)." The timeless 1960s lullaby has been famously covered by Elvis, George Jones, Al Green and Lyle Lovett, among others.

But even for those not familiar with Campbell's work, his Adiós rendition of "Funny (How Time Slips Away)" is one that lingers. As USA Today notes, once Campbell laid down his vocal track for the song, his producer Jackson got in touch with Buddy Cannon, a Nashville-based producer in the studio with Nelson at the time. Nelson added his vocals to be overlaid with Campbell's and in a masterful edit, it is transformed into the powerful duet we hear on the studio track. Lamentably, Campbell passed away before ever getting to hear the final cut, plunging it deeper into nostalgic sobriety.

From the opening verse, Campbell's voice splinters into sadness—"Well hello there, my it's been a long, long time"—hitting you like a knock-knock joke without a punchline. Meanwhile, Nelson's signature timbre swings into your eardrums as if he's happily lazing on your living room couch. Campbell and Nelson's call-and-response vocals maintain their distinctiveness, yet thrum with a unity only a decades-old friendship can possess (the two met while on tour in the ‘60s with Buck Owens and His Buckaroos).

Sure, Campbell's voice never quite cracks, but you can hear its subliminal descent in a few well-placed gaps of silence. As any kindred brother would, Nelson picks right back up where Campbell trails off. The listener soldiers on. And isn't that what the Rhinestone Cowboy would have wanted?

Listen to their recording of "Funny (How Time Slips Away)" below.