It sometimes seems that country music doesn't always recognize a star when one all but falls in its lap.

Five years ago, when a 22-year-old singer from Muskogee, Okla., named Carrie Underwood was crowned champion of the fourth season of American Idol, a major crossover success story bloomed.

Before her first album was even complete, an initial single, Inside Your Heaven, became an instant pop sensation that knocked aside heavyweights including the Black Eyed Peas, Mariah Carey, 50 Cent and Gwen Stefani. It became a quadruple-platinum hit.

Inside Your Heaven entered Billboard magazine's all-genre Hot 100 chart at No. 1 in June 2005. It debuted on the Country Airplay chart at No. 59. The chart went only to 60.

A June 2005 post on the Web site of Country Music Television said, "There is still time for country radio programmers to make up their minds," implying that Underwood's commercial future in a Nashville marketplace was hanging in the balance.

A bona fide "Okie from Muskogee," to quote the title of the landmark Merle Haggard hit, and a native of the same state that gave country music Reba McEntire, Vince Gill and Toby Keith knocks on Nashville's door as an already proven hit-making force, and the industry's reply is, "Uh, we'll see"?

OK, let's review more current stats. Combined sales of Underwood's three studio albums — the debut Some Hearts, 2007's Carnival Ride and last year's Play On — have now passed the 12 million mark. Even though Inside Your Heaven stalled at No. 52 on the country charts, Underwood became a No. 1 country mainstay.

What's impressive here isn't so much the songs that hit big, but the ones that didn't. Of her 13 most recent singles, only three failed to reach No. 1. One of those, 2006's Don't Forget to Remember Me, made it to No. 2. She comes to Rupp Arena on Sunday on the heels of another, the current hit Undo It, which sits at No. 11 this week but is on the rise.

Needless to say, country music invited itself and fast to this party.

One could argue that Nashville's initial hesitancy toward Underwood's music was because there were so few leanings toward country in the songs with which she introduced herself. After all, among the tunes Underwood sang as a finalist on American Idol was Heart's 1987 rock anthem Alone — not exactly standard country fare.

But these days, giving the cold shoulder to a country act with a rock 'n' roll accent is, at best, naïve, and at worst, hypocritical. Contemporary country has co-opted so much from rock and pop turf — Keith Urban's giddy guitar rampages, Rascal Flatts' sentimentalized hits, Taylor Swift's mainstream pop glow — that traditional inspirations haven't just been pushed to the back seat. They've been locked in the trunk.

And so country, rock and pop coexist happily onstage and off for Underwood. At her last performance at Rupp Arena a mere two years ago (as the opening act for Urban), the singer offered a Vegas-level production, full of costume changes, lighting effects, plentiful hits and a moment that was especially telling of where the roads of rock and country collided in her music: a feisty but G-rated version of the Guns 'N Roses rocker Paradise City.

That one didn't seem to bother the country music industry. Nor did a return visit to American Idol in 2009, when she performed the Motley Crue power ballad Home Sweet Home. Five years of continuous hits, one supposes, provides the kind of industry clout that allows an artist to call her own stylistic shots. These days, Underwood could go on TV and sing a medley of The Ramones' hits, and Nashville would embrace it.

But image helps. And Underwood's image remains as unblemished these days as that of, say, Swift. Sure, high-profile romances have landed her unavoidably in the tabloids. And her engagement to Canadian hockey star Mike Fisher earned almost as much notice in a feature story last week in USA Today as her music. But remarkably little controversy surrounds Underwood these days. Hence the wholesomeness of one of her best-loved performance songs, All-American Girl, continues to play out for her public.

There also is something to be said for the other side of the performance coin — specifically, the view that the prospective careers of all American Idol winners lead to oblivion. Admittedly, most have, and in all likelihood, most will. The mere concept of a quickly created "star" almost guarantees a level of stardom that dissolves as quickly as it ignites.

But none of the Idol champs, not even season one insta-celebrity Kelly Clarkson, has matched Underwood's accomplishments over the past five years. Underwood has scored five Grammy wins, including a 2006 trophy for being one of only three country acts to win for best new artist. She also became the first woman to win consecutive entertainer of the year honors from the Academy of Country Music.

So, yes, Nashville was surprisingly hesitant in answering the door when Underwood introduced herself in 2005 — especially given how intensely the pop world already had courted the singer. But Underwood has found her home now. And Nashville, after no small level of persuasion, has found her.