Why does Carrie Underwood sometimes get booed on stage? How does she keep her "messy" life in control? And in which '80s music icon did she have "faith, faith, faith?"

In an exclusive segment for 'Katie Couric's All Access Grammy Special,' Underwood, who's a vegetarian, reveals that she's been booed for discussing that lifestyle choice in certain cattle-farming parts of the country. And although she doesn't eat meat, she likes "mustard on everything." She also admits she's fairly obsessive about keeping her refrigerator and kitchen pantry in order with "a certain shelf for everything and all the labels turned out." She takes the same care for her DVD collection, keeping the discs in alphabetical order.

The three-time Grammy winner, nominated this year for 'Last Name,' says her mom is her best friend and biggest influence on her life, but it's singer George Michael who was Underwood's first great musical inspiration.

"He was the first voice I could ever pick out," she says. "I remember singing everything that he did with Wham! and then by himself when I was very young. I knew all the words and still do."

As for more current music, the Oklahoma-born superstar says one of her new favorite artists is Safetysuit, a rock band also originally from her home state -- and also currently based in Nashville. Underwood adds that she has "love, love, love" for New Kids on the Block and also for fellow 'American Idol' champ David Cook's debut album.

'Katie Couric's All Access Grammy Special,' featuring past and present Grammy nominees, including Taylor Swift, Justin Timberlake and Katy Perry, airs Wednesday, February 4 at 9 PM ET on CBS.