When Blake Shelton announces a free concert in Nashville, complete with food trucks and beer ... well, you drop everything and head to the show. The country star delighted fans who came to Pickin' on the Patio on Wednesday (Sept. 23) by performing his tried-and-true hits as well as his current single, "Gonna."

More than 10,000 country fans, according to the Tennessean, showed up to Warner Music Nashville to see the show, which Shelton took the liberty of announcing via Twitter late last week. The singer admitted that he wasn't “really prepared” for the concert, because he didn't know what the crowd would look like, but he said that “no matter what, I’m going to have a blast."

“I don’t know what’s going to happen on this thing,” Shelton admitted, joking, “My goal is 2 million people, but I’ll settle for 30,000."

At the show, Shelton told the crowd that he was "shocked and honored" to have drawn such an audience.

The singer appeared just after 6PM and kicked off the show with "Neon Light." Highlights of Shelton's 12-song set included "Boys 'Round Here," "Sangria," "Mine Would Be You," and "Gonna," which you can watch above.

"This is like a real party out here," Shelton announced before launching into the new single.

The Oklahoma native's show was the final installment of Warner Music Nashville's Pickin' on the Patio event for 2015. Cole Swindell, Charlie Worsham and Jana Kramer have all played the event.

Shelton's upcoming greatest hits record, Reloaded: 20 #1 Hits, will be released on Oct. 23. Fans can pre-order the album on Amazon.

See Photos From Blake Shelton's Pickin' on the Patio Concert

How Well Do You Know Blake Shelton?