ATHENS, Ala. (AP) — 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.

About 5,500 people turned out for the show in Athens, about 100 miles (161 kilometers) south of Nashville, said Athens Police Department Capt. Brett Constable. The concert 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.