Shut the front door.

Or, at least that's what we imagine country music or The Voice fans will be saying after reading this story.

Country music superstar and celebrity judge Blake Shelton tweeted on Thursday he is playing an impromptu, free, first-come first-serve concert Thursday night at the Grizzly Rose.

The country music club quoted Shelton's tweet a few minutes later, and told fans the line will start on the east end of the building. The show is 21+.

The singer/songwriter has been tweeting mysteriously all week about impromptu shows in various cities.

On Wednesday, he tweeted from Kansas City. Then, he tweeted a blurry picture of a highway that could have been anywhere, but now we can assume was likely on I-70 or I-80.

Anyway, Shelton tweeted the doors will open at 6:00 Thursday.

We'll update this story as we get more information.