With girl-next-door good looks and a hint of Oklahoma twang in her voice, Carrie Underwood has the makings of a country-music star.

Apparently, fans of the hit television show "American Idol" saw the crossover potential in Underwood, whose affinity for country ballads didn't deter her from winning the fourth installment of a competition that is geared more toward audiences of MTV than the Grand Ole Opry.

Since winning "Idol" in May, Underwood's career has been in full-throttle mode, from promoting her single, "Inside Your Heaven" — which debuted atop the Billboard Hot 100, Pop 100 and Country Singles charts — to making rounds on talk shows and crisscrossing the country on the American Idols Live! tour.

The traveling show, featuring the top 10 finalists from the television show, including runner-up rocker Bo Bice, will stop at the Everett Events Center on Tuesday night.

Underwood's ascent from unknown singer to "American Idol" has a Cinderellalike flavor: A young woman grows up on a farm in bucolic Checotah, Okla., gets plucked from obscurity and is catapulted to a $1 million recording contract and nationwide fame. A media blitz and high-profile endorsements (with Hershey's and Skechers footwear) solidify the fresh-faced 22-year-old's place in pop-culture lore.

Underwood spoke recently about her Idol-ized life.

"It has been crazy," Underwood said in a phone interview during a tour stop in Massachusetts.

"Everything has been a complete whirlwind, and I'm just trying to keep my head on straight. It's important to keep in touch with people who knew me before, and I talk to my mom every day [to stay grounded]."

Although Underwood had minimal singing experience, aside from church and school pageants, she persuaded her mother to make the eight-hour drive from their home to St. Louis to audition for "American Idol."

Since Underwood's win, life has been at turns surreal and gratifying.

"I get to do what I love every day. It's the best thing," she said. "If it all ends, I have had the best time in my life."

With a kind of vintage country-Western sound and a palpable sweetness, Underwood made an impression on the judges early on, garnering admiration from the churlish but often spot-on Simon Cowell.

Though Underwood is known for her angelic voice and calm presence on stage, she's quick to concede she doesn't know where it all comes from.

"Nobody else in my family is musically inclined," she said.

But singing live in front of a raucous live audience — plus a viewing audience of more than 20 million each week — has forced Underwood to overcome a natural diffidence.

"I'm a very shy person," she said. "But I feel like I'm coming out of my shell a little more."

For Underwood, there were no reservations when it came to expressing her affinity for country music, even when she was performing songs from the disco era or pop hits from the 1980s.

"It was a little strange because I thought people might not relate to me," she said. "A lot of people have this funny stereotype about country music. But whether I won or not, I wanted the type of contract to do a country record. That's where my heart is."

After the tour, Underwood will hunker down in a studio in Nashville, Tenn., to record her debut full-length album, a genuine country-Western effort.

Fans may need not worry that Underwood will succumb to the pressures of the music industry to taint or tart up her image. Tammy Wynette's "Your Good Girl's Gonna Go Bad" isn't likely to be Underwood's theme song.

"I don't ever want to be risqué or compromise my morals or values for any kind of offer," she said. "I just want to be me."

Tina Potterf: snohomishcounty@seattletimes.com