Thousands of country music fans battled the Nashville sun and 90-degree heat for the official start to this year's CMA Music Festival Thursday morning (June 9) with an 11-song performance by Gary Allan.

"Good to see everybody up so early," he told the jam-packed crowd at Riverfront Park. "I was just hoping someone else was gonna do it with me."

Throughout Allan's entire 45-minute set and even after, throngs of concertgoers continued to pile in the grassy area in hopes of staking claim on an undiscovered patch of green.

Despite a few quips at the start of his set, the seasoned performer ran through a string of his greatest hits including "Right Where I Need to Be," "A Feelin' Like That," "Nothing On but the Radio" "Man to Man," "She's So California," "Smoke Rings in the Dark," "Songs About Rain," "Best I Ever Had" and "Watching Airplanes." He also performed music from his most recent album, Get Off on the Pain, including the album's title track and "Kiss Me When I'm Down."

Other artists scheduled to perform throughout Thursday afternoon include Emerson Drive, Colt Ford, Jack Ingram, Sammy Kershaw, Craig Morgan, James Otto, Jake Owen, the Randy Rogers Band and Steel Magnolia.

Sightseers venturing nearby Nashville's Bridgestone Arena may also spot a few familiar faces playing Lay's Stage. Morning and afternoon performances include something for country fans of all ages. Newcomers like Blackberry Smoke and Edens Edge will share the stage with Lynn Anderson, Rhonda Vincent and Grand Ole Opry member Jeannie Seely, to name a few.

For those interested in autographs (and air conditioning), the Nashville Convention Center will house plenty of booths for signatures and personal meet-and-greets throughout the four-day festival including artists like Martina McBride, Trace Adkins, Blake Shelton and many others. The Country Music Hall of Fame and Museum will also feature these opportunities with Josh Thompson, Tracy Lawrence (Thursday) and Hall of Fame member Tom T. Hall (Friday).

Nightly concerts held at LP Field, also home to the Tennessee Titans, remain the largest of the festival's concerts. Thursdays lineup includes Jason Aldean (with special guest Kelly Clarkson), Easton Corbin, Sara Evans and Brad Paisley. The Zac Brown Band will be joined onstage by Alan Jackson, Amos Lee, Sonia Leigh and Randy Travis. American Idol finalist Casey James and bluegrass veteran Ricky Skaggs are set to perform acoustic sets during set changes.

Friday night's concert at LP Field features Dierks Bentley, Lady Antebellum, Reba, Ashton Shepherd, Sugarland and Keith Urban. Saturday evening's show features Trace Adkins, Little Big Town, Martina McBride, Rascal Flatts, Josh Turner and Chris Young. The festival closes Sunday night with Taylor Swift, The Band Perry, the JaneDear Girls, Miranda Lambert, Darius Rucker and Blake Shelton.

Check out full coverage from the CMA Music Festival.