But the story of it goes back quite a way and the song's writer Ned Sublette tells it in his excellent book The Year Before the Flood about his time in New Orleans before Katrina and the flooding.
Sublette had written the song in '81 and at one point -- when Kinky Friedman was going to make a movie of his novel A Case of Lone Star -- the three of them were going to record it: "But it never happened."
"I premiered it for an audience of no more than twenty in a SoHo basement performance space called InRoads," writes Sublette, "accompanied by George Lewis on sousaphone. The next gig I did someone requested the song. It went on like that, taking a life of its own from the beginning."
He says he'd composed it on the family piano when he was back home from New York visiting his folks in Portales at the height of the Urban Cowboy phase.
"I was inspired by being back in the Land of Protestant Repression, and by God, I do know how a West Texas waltz should sound. I made a good recording of it in '84 in Lubbock for an album I made with Lloyd Maines and my band that cost a fuckwad of money and never came out (never mind).
"Then one night in 1987 my friend Tony Garnier slipped Willie a cassette of the song when they coincided on Saturday Night Live. It became a Willie Nelson band bus favourite immediately. Willie started mentioning it in interviews, to my dropped-jaw astonshment. But he'd never recorded it."
Then 17 years later, prompted by Brokeback Mountain, Willie did. The people putting together the music for the movie turned it down "because it was a funny song and they were making a tear-jerking movie. But you know, the song isn't all that funny. It depends on how you do it."
Sublette says that at the same time as he heard Willie had recorded it he (Ned Sublette) received a Guggenheim fellowship.
"I seem to remember that at the end of the reception, after multiple glasses of wine, I sang Cowboys are Frequently Secretly in its entirety, a cappella, in full voice, to a circle of people.
For more oddities, one-offs or songs with an interesting backstory use the RSS feed for daily updates, and check the massive back-catalogue at From the Vaults.