Stephen Colbert paid tribute to his friend John Prine on Wednesday night’s edition of “The Late Show,” by airing a never-before-seen duet with the ailing folk singer-songwriter.

In his introduction to their collaboration on “That’s the Way the World Goes Round” — a hauntingly beautiful take on the 1977 cut by Prine, which was taped for the the late-night gabfest in 2016 but never broadcast — an emotional Colbert notes: “I’d like to take a moment right now to send out a personal message to a friend. Last week, our friend — and yours — the musical great John Prine was placed on a ventilator with coronavirus symptoms. My thoughts are with John and his wife, Fiona, and his family. And everybody out there touched by this virus.”

Prine, 73, was hospitalized this week in critical condition after testing positive for coronavirus. Though the status of his health was later clarified to “stable,” by his wife, Fiona Whelan Prine, the Maywood native remains in intensive care on a respirator.

Colbert calls the performance “one of the happiest moments I’ve had on my show,” prophetically adding: “We’ll probably do this for the internet. Unless, you know, something terrible happens and we have to cheer up the world on the TV show.”