It's a clash of two generations in this Round 1 March Bandness matchup. Rascal Flatts, the greatest country trio of the 2000s, are facing Diamond Rio, a band that was equally strong in the '90s. Whose fans will step up to get them to the next round of this contest to find the best band in country music history? 

Diamond Rio comes in as the underdog only because they've been out of the spotlight in recent years. Their resume -- including Grammy Awards and multiple CMA and ACM awards for Group of the Year -- stands up nicely to the Flatts' catalog and trophy case. Vote for your favorite country group below before voting for other Round 1 matchups. The winner of this round will go on to face the winner of battle between Eli Young Band and Sugarland.

Fans are allowed to vote once every hour. Any voter found to be outpacing that rule will be deemed ineligible, forfeiting their votes. Voting for the round one matchups will end on Sunday March 17 at 11:59PT ET.

The overall March Bandness winner for 2013 be announced on April 8, the day of the NCAA national championship basketball game.