Charles Kelley is putting the finishing touches on his upcoming solo project, and it looks like he might have a very special guest on one of the tracks.

The Lady Antebellum singer has been working in the studio, and he recently posted a teasing picture to Instagram of the board at the studio where's he's working on mixing the tracks. Among the labels on various faders, one is clearly marked "Miranda," which has prompted widespread speculation that Miranda Lambert has contributed vocals to a song on the forthcoming project.

Kelley released the title song, "The Driver," in September. The song features guest performances by Dierks Bentley and Eric Paslay, and it earned Kelley a Grammy nomination for Best Country Duo/Group Performance. The singer says the sound reflects a grittier, edgier side of his music than he's able to capture with Lady A.

“My influences have always been more, kind of ‘70s and Southern rock, Bob Seger, California country kind of feel," he tells Taste of Country. "So kind of what I wanted to capture with this project and the timing was perfect.”

Kelley announced a solo tour in October, revealing a string of club and small theater shows that were to run from Nov. 28 through January of 2016 before wrapping up in Las Vegas. But the tour got off to a rocky start, with Kelley canceling shows in Charlotte, N.C. and Atlanta just days before they were to have taken place. The bulk of the remaining dates have now been postponed until early in 2016, which is also the time frame for the release of his EP.

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