Country music became the voice of mainstream music in the '00s, spreading its wings stylistically to cover a wider range of artists and generate hits that cross the genre's borders.

As commercially successful rock acts continue to age and pop acts rarely show decade-to-decade staying power, country music has become a haven for career artists, even those who got their starts outside of Nashville.

For the first time in country music's 80-year existence, crossover became a two-way street. The old guard at the labels and radio used techniques associated with pop and R&B, located and embraced discarded rockers who had a following with country fans and, as the decade closed, developed the fastest rising superstar in the business, Taylor Swift [ tickets ].

During the course of the decade, country music opened its doors to the Eagles [ tickets ], Bon Jovi [ tickets ], Kid Rock [ tickets ], Jimmy Buffett [ tickets ] and Darius Rucker of Hootie & the Blowfish; discovered that the boy band development process can work with adults in Nashville ( Rascal Flatts [ tickets ], most prominently); and that an audience exists for more traditional country artists (Alison Krauss and Lucinda Williams, for example), as well as for acts that hew close to the singer/songwriter mold of the early 1970s with just a pinch of twang (Sugarland, One Flew South, Little Big Town).

Several of its established stars from the 20th century--Dixie Chicks, Johnny Cash, Yoakam, Merle Haggard, Charlie Louvin, Porter Wagoner--found new audiences outside the country mainstream

The blossoming of 19-year-old Swift in '09 follows a familiar pattern at the close of each decade. The impressive class of '89 artists scoring their first country hits included Garth Brooks, Clint Black, Alan Jackson, Travis Tritt and Dwight Yoakam; Shania Twain, Dixie Chicks and Faith Hill [ tickets ] crashed the '99 party dominated by boy bands and teen-oriented acts.

The country format became No. 1 in popularity and number of stations. It had an affect on the singles chart, too: an average week in 2009 saw 21 country songs in the Billboard Hot 100, compared to 14 rock tracks.

Country music was the one genre to reduce the disconnect that has existed in rock and R&B for more than a decade: Stars who sold the most records were also the stars who sold the most concert tickets.

Kenny Chesney [ tickets ] sold more concert tickets than any other act in the decade, according to industry tracker Pollstar. Chesney, the third highest-grossing artist in the decade, brought in $455.6 million at the gate, behind only the Dave Matthews Band and Celine Dion.

Of the top 25 acts in Pollstar's list of top grossers, eight had connections with country music. One of the more interesting tallies for the decade involved country superstar Tim McGraw [ tickets ]. On tours with his wife faith Hill, the pair pulled in $189.9 million (No. 22) and on his own he grossed $133.7 million (No. 42). If combined, McGraw's gross of $323.6 million would have him at No. 8 between Madonna and the Eagles, which pulled in $313.4 million.

While Chesney was the No. 1 concert attraction, he was the decade's No. 2 country act according to Billboard magazine, whose charts are based on sales figures compiled by Nielsen Soundscan. Toby Keith [ tickets ], who had the 11th highest concert box-office results ($241.4 million), was Billboard's top country artist of the decade. The magazine placed his album "Unleashed" at No. 61 on the top 200.

Rap and R&B acts, with a couple of pop stars, dominated the decade in the sale of recorded music, Eminem and Usher placing one-two on Billboard's top of the '00s list. Overlap between Pollstar's top 50 and Billboard's top 20 was minimal, as only Nickelback and Britney Spears made it onto both lists.

Rascal Flatts was No. 16 on Pollstar's list at $222.4 million; their albums "Me and My Gang" and "Feels Like Today" were Nos. 50 and 52 on Billboard's best sellers for the decade.

Naturally, Billboard's list for the decade was dominated by albums released in the first half of '00s. Swift's two albums--her self-titled debut, which spent more weeks on the Top 200 than any other album in the decade, and "Fearless"--came in at Nos. 53 and 56 respectively. Despite her selling out every stop on her '09 tour within minutes, she did not make it onto the concert top 50.

The country albums that made a dent in the pop world were Carrie Underwood's "Some Hearts" at No. 14 for the decade; the "O Brother, Where Art Thou?" soundtrack at No. 20; the Dixie Chicks' "Fly" at No. 25 and "Home" No. 28; Faith Hill's "Breathe" at No. 31; and Shania Twain's "Up!" at No. 35.