Kacey Musgraves recently celebrated nine years since her hit “Pageant Material” song debuted.

The track came from her hit album of the same name. For one of the songs on the album — “Are You Sure” — she called on famous friend Willie Nelson to sing on.

There is a story of how the two connected to team up for the song — which Nelson originally released in 1965 — a story Musgraves recently opened up about in detail on social media.

“It was 2014 and the first time I ever smoked with Willie,” she write on Instagram. “I was on the road opening for he and Alison Krauss, and he had us up on his bus for some coffee and smoke before he started his set.”

The singer continues that the three of them shot the breeze in his tour bus, touching on a range of topics.

“I asked him ‘Hey, do you ever play ‘Are You Sure’?’ He exhaled a big puff and blinked and said, ‘Are you sure this is where you wanna be?’ looking surprised I knew such a deep cut then pulled his guitar from magically out of nowhere.”

She notes that she wasn’t all there during that moment, and had to continually remind herself that this surreal moment was indeed happening.

From that moment, Nelson would join the singer on “Are You Sure.”

“It’s a good thing there is visual record of this moment in my life — otherwise I wouldn’t believe that it wasn’t just some hazy, sparkly, pipe dream that never actually happened,” she quips.

This Instagram post comes on the heels of Nelson’s recent cancelation of shows.

The 91-year-old canceled his Friday June 21 show due on doctor’s orders.

Then, just a few days later, the singer canceled yet another show on Wednesday June 26.

The tour runs through September. Nelson’s newest social media posts reveal that Lukas Nelson and special guests will play several of his hits until he is able to return.