Fans who turned up at the famed Bluebird Cafe in Nashville on Tuesday (Oct. 9) got the ultimate surprise when one of music's biggest superstars, Ed Sheeran, made an impromptu appearance.

Devin Dawson was making his Bluebird debut, with songwriters David Hodges, Amy Wadge and up-and-comer Jillian Jacquline joining him in the round (each songwriter takes a turn performing a track that they wrote or co-wrote). But Sheeran stole headlines when he too hopped into the round for a performance of his Grammy-winning hit "Thinking Out Loud." The pop hit is a co-write with Wadge, who played guitar while they engaged in a passionate duet.

Relive the Greatest Country Duets Ever

Jacquline posted a video of Sheeran's surprise appearance on Twitter, writing, "we had an extra special guest last night for @zdevin's first @BluebirdCafeTN round," alongside a video that captures her staring in awe as the two songwriters perform the popular song.

"@teddysphotos joined me on this and it made my year," adds Wadge in an Instagram sare of the performance.

Sheeran recently performed at Nissan Stadium and also came onstage during Bruno Mars' sold-out show at Bridgestone Arena in October, also to sing "Thinking Out Loud" and perform "Happy Birthday" for Mars. The "Shape of You" singer has not kept his admiration country music under wraps, with a friend of his posting a video of the two singing Luke Combs' "When it Rains it Pours" while on a beach vacation.

"Country music is some of the best-written music in the world, so yeah, one day, I would keep my mind open to doing a country record," Sheeran told Yahoo! in 2013.

Stars Who Have Unexpectedly Gone Country

More From KIKN-FM / Kickin' Country 99.1/100.5