Carrie Underwood surprised fans at a Dick's Sporting Goods location in Nashville when she went undercover to wait on shoppers who were browsing her clothing line, Calia by Carrie.

In the video above, the country superstar dons a dark wig and glasses to pose as a Calia by Carrie representative, first goofing around by posing by some of her own posters, then waiting on some unsuspecting shoppers who are looking for some active wear.

"I'm the Calia rep from the head Dick's Sporting Goods store. I'm here for the day, just kind of checking things out," she tells one woman. She goes about her day as an ordinary retail employee, helping one shopper look for something in pink, finding a vacant dressing room for another and asking customers to let her know if there's anything she can do to help them.

"I know all things Calia ... I'm an expert," she tells one shopper with comic understatement, boasting to another, "I know the designer." She can't resist having a little fun with some of the unsuspecting customers, asking them if they like Carrie Underwood's music and what songs they know.

"You look familar," one woman says. "Do I ...?"

"It's my first day here," Underwood quickly replies. "I've never been to this store before."

"I used to be in the music business, and I gave it all up to come work at Dick's Sporting Goods," she tells another woman with a perfectly straight face. But it's a step too far, as the woman smiles broadly and says, "Okay, I recognize you ...  are you Carrie Underwood?"

She's just one of several shoppers who sees through Underwood's ruse over the course of the day. The singer ends up ditching the wig, handing out hugs and taking pictures with a number of fans, and caps it off by leading a singalong of her hit, "Before He Cheats," over the store's loudspeaker.

Afterward she posed for a group picture with her temporary co-workers, which she shared via Twitter.

Check Out Carrie Underwood's Amazing Storyteller Tour Outfits

Watch Carrie Sing Dolly Parton: 

More From Taste of Country