Johnny and June. Brooks & Dunn. Sugarland. Some of the best country music has come from duos who broke the mold and set the bar with epic harmonies, skilled songwriting and all-around great stage presence. And at the 2016 CMA Awards, five acts have the chance to take home the trophy for Vocal Duo of the Year.

Florida Georgia Line might very well take home their fourth consecutive win, but with steep competition from two other male duos, a spunky and refreshing female pairing and a husband and wife whose musical partnership tragically ended with her death, the 2016 CMA for Vocal Duo of the Year is anyone's to win. Read on to learn more about each of the nominees, and tell us who you think will win!

Ever since their first nomination in 2013, Florida Georgia Line have swept the Vocal Duo of the Year category, taking home the award in 2013, 2014 and 2015. And with the release of their most vulnerable record yet, a 60-city U.S. tour and a big win at the ACM Awards (not to mention that surprise Backstreet Boys collaboration), some may assume that a 2016 win at the CMAs is all but in the bag. But watch out, FGL -- there's some pretty great duos nipping at your heels!

When Joey + Rory burst onto the scene on the CMT reality competition Can You Duet in 2008, no one could have guessed that their music and their love story would completely enthrall the county music world. But with milestone after milestone, the couple garnered a dedicated fan following, earned critical and commercial success and even started a family before Joey Feek's life was tragically cut short when she passed away from cervical cancer on March 4. Less than a month before her death, Joey + Rory released their Hymns That Are Important to Us album, which earned them their first No. 1 record.

When it comes to dedicated duos, you'd be hard-pressed to find pairs more committed (or in sync!) than siblings -- and Brothers Osborne are a perfect testament to that fact, as is their unforgettable year. Not only did John and TJ Osborne release their debut album, Pawn Shopto critical acclaim in January, the brothers also earned their first No. 1 single and recently kicked off their first-ever headlining tour. No question, it's been a big year for Brothers Osborne -- but big enough to help them win Vocal Duo of the Year?

Another awesome male duo, Dan + Shay are also nominated for Vocal Duo of the Year at the 50th annual CMA Awards. The highlight of the year for Dan Smyers and Shay Mooney? Whether it was the release of their sophomore album in June, the announcement of their fall Obsessed Tour or that smooth and sultry collaboration with Boyz II Men, it's hard to pick just one! And wouldn't a win for Vocal Duo of the Year just be the sweetest icing on the cake?

Last but certainly not least, there's the only all-female duo to be nominated for Vocal Duo of the Year this year, Maddie & Tae. The pair took home two wins at the 2016 Radio Disney Music Awards, for Favorite Country Artist and Favorite Country Song, and add to that an anti-bullying ballad in "Sierra," and 2016 makes for a particularly poignant and powerful year for the girls. Do you think it will be enough to give Maddie & Tae the edge for Vocal Duo of the Year?

Who should win Vocal Duo of the Year at the 2016 CMA Awards? You can vote in the poll below as often as once an hour until 11:59PM ET on Oct. 31. We’ll compile the results for our readers vs. staff predictions the following day (Nov. 1).

The 2016 CMA Awards are set to air live from Nashville's Bridgestone Arena on Nov. 2 on ABC at 8PM ET.

Surprises and Snubs Among the 2016 CMA Awards Nominees

Test Your CMA Awards Knowledge!

More From TheBoot