Jimmy Buffett and the Coral Reefer Band may have three concerts in Nashville slated for next month, but that didn't stop them from playing a pop-up show at a venerable rock club across town.

The "Margaritaville" singer even brought friends. Kenny Chesney joined him onstage on Monday night (June 21), and former Vice President Al Gore was in the audience.

The show at the Exit/In on Elliston Pl. on Nashville's west side featured a loose set of hits and surprises. Chesney, for example, acknowledged that singing his own "Back Where I Come From" was a curveball. He was also onstage to sing Buffett's signature song:

The Tennessean points out that Buffett has shows at the Ascend Amphitheater on July 6, 8 and 16 and is currently in town rehearsing. He has an interesting history with the city, having been the first person to actually perform at the Exit/In 50 years ago. The club's co-founder recalls him wandering in off the street as the club was under construction; he'll be part of the venue's 50th anniversary book, Exit/In: 50 Years and Counting.

On his own Instagram page, Buffett shared footage of a few songs. The performances show a more reserved crowd than one would typically find for one of his concerts. The show wasn't announced, leaving even some of country music's celebrities out in the cold.

"Are you kiddddingggg…how did I miss this," Chris Lane commented on Chesney's post. "That would have been epic."

Last summer, Buffett was set to make his Grand Ole Opry debut, but the effort was nixed due to rising COVID-19 cases. There has been no rescheduled date.

10 Hottest Songs for Summer 2021

Summer 2021 needs a great soundtrack, and country music's biggest stars and hottest newcomers are supplying. Find songs from Little Big Town, Jon Pardi, Dierks Bentley and Miranda Lambert on this 10 Hottest Songs for Summer 2021 list.

Newcomers Willie Jones and Walker Hayes also make the list with earworms we don't want to quit. Not every hot summer song needs to be a good-time party song, and not every good party song will make a great summer playlist. Our Top 10 embraces a range of emotions and experiences. What would summer be without summer love or summer heartache, or a bit of nostalgia?

Scroll down to see all 10 songs on this list of the hottest summer country songs. It's part of Taste of Country's summer Hot List, an annual report on the songs and artists set to bake this year.