Keith Urban plays free pop-up concert outside a Buc-ee's store in Alabama

ATHENS, Ala. -- Country singer Keith Urban gave just a few hours' notice before performing a free concert Friday night in the parking lot of a large convenience store and gas station in north Alabama.

Hundreds of people turned out for the show in Athens, about 100 miles (161 kilometers) south of Nashville. It was outside a Buc-ee's, a chain of roadside stores known for barbecue.

“I came down to this Buc-ee's about a month ago. And when I left, I went, ‘It’d be kind of fun to do a show there,'” Urban told the crowd during the concert, according to an Instagram video posted by WAFF-TV in Huntsville, Alabama.

Urban said his “cave man brain” told him it would be fun to set up a little stage for a small audience.

“I swear to you, I thought maybe 100, 200 people,” Urban said as a video showed a larger crowd.

People started gathering hours before the show, news outlets reported.

“I was at work and we heard it on the radio that there was going to be a surprise concert at Buc-ee’s in Athens,” Cindy Wilson told FOX 54 WZDX-TV in Huntsville. “And I was like, ’Oh my God, it’s on my way home.' And it’s 15 minutes from my house. So I couldn’t believe it.”

While he was at the store, Urban also worked behind a food counter. A video showed him wearing a Buc-ee's T-shirt and apron as he poured barbecue sauce on some brisket and chopped the meat into smaller pieces.