Ed Sheeran delighted fans in Tennessee on Wednesday night (04Sep13) when he joined his pal Passenger onstage for an impromptu duet.

The A Team hitmaker flew in to Nashville from Los Angeles on Tuesday (03Sep13) just to catch the folk star in concert at the Mercy Lounge, and he decided to get involved in the intimate gig, entertaining attendees by teaming up for their collaboration Hearts on Fire, before performing a cover of Blackstreet's classic R+B track No Diggity, including an excerpt of Macklemore + Ryan Lewis' Thrift Shop.

Sheeran tells RollingStone.com, "Mike's not only one of my best friends, he's just one of the best singer-songwriters I know.

"One thing that I really love about me and Mike is whenever we meet up, we always sit somewhere and play each other tunes. It's kind of like poker - you have to show your best hands."

He jokes, "We're gonna start a group called the Chixie Dicks. It's gonna be the new Simon and Garfunkel."