The Single of the Year category is bound to be a close race in the 2013 CMA Awards. Three of country's most established acts are competing against two hot newcomers for the prize. 

Tim McGraw brought in Taylor Swift and Keith Urban for 'Highway Don't Care,' which took his career in a slightly new direction. Miranda Lambert did what she does best with 'Mama's Broken Heart,' the kind of song that virtually no other female artist in Nashville could get away with. Darius Rucker borrowed 'Wagon Wheel' from Old Crow Medicine Show and scored one of the biggest hits of his career.

Florida Georgia Line were virtually unknown a year ago, but they've been breaking chart records that have stood for decades with 'Cruise.' And Kacey Musgraves -- who also co-wrote 'Mama's Broken Heart' -- scored a hit right out of the gate with 'Merry Go 'Round,' which helped her debut album, 'Same Trailer Different Park,' debut at No. 1 in its first week of release.

Which one deserves to win Single of the Year at the 2013 CMA Awards? Vote as often as once an hour, and we'll tabulate the results and use them for our 2013 CMA Awards winners predictions the week before the show.