Rascal FlattsRascal Flatts hosted a party in Nashville Tuesday night to celebrate their 10 years as recording artists and to thank country radio programmers -- in town for the annual Country Radio Seminar -- for playing their music throughout the decade. The trio's songs have been played more than 3.2 million times on the air.

People milled about in one of the ballrooms at Music City's Renaissance Hotel, exchanging pleasantries, toasting each other and watching photos of the guys over the years flash up on two giant screens flanking a stage with three stools and a piano. Gary LeVox, Jay DeMarcus and Joe Don Rooney came out on the stage to a nearly standing-room-only crowd, and the party began with a video tribute, sometimes to the embarrassment of the guys on stage, forced to revisit some pretty cringe-worthy outfits and hairstyles from when they first started out!

They began the acoustic set with their first hit, 'Prayin' for Daylight,' and followed it up with the "first song they ever sang together as Rascal Flatts," which was Shenandoah's 'Church on Cumberland Road.' But before they could really kick into the song, Shenandoah's former lead singer Marty Raybon surprised the crowd when he came out on stage and traded vocals with Gary and the guys. Then the trio asked him if he could stay and do another song, the 1990 hit 'Ghost in This House.' Gary said prior to getting their record deal, they played shows from 9:00 pm to 3:00 am and would play "every Shenandoah song over and over and over ... [so] it's an honor to call him friend ... [Marty] was a great learning tool." The guys then joked, "So much for 20 years of Rascal Flatts." 'Fast Cars and Freedom' came next with 'Bubba's Girl,' a parody of Rick Springfield's 'Jessie's Girl,' which they did during their first radio tours in 2000, performing in conference rooms all over the country.

The guys took a small break to check out other photos from the past, and then awarded a signed guitar to Columbus, Ohio, station WCOL to comemorate the most plays of their debut single. More music followed with their 2005 chart-topper 'Bless the Broken Road' and 'What Hurts the Most,' which hit the top of the charts in 2006. The guys wrapped it up with a hearty thank-you and told radio they were in the midst of recording their new album, which is expected to be released this fall.

Rascal Flatts is definitely 'Unstoppable' -- they left following their performance at CRS to head to a show in Sioux City, Iowa.