There was a time in country music where two was the accepted number of acts that were booked together for a concert tour. Those days are nearly gone.

Kenny Chesney, of course, has his massive summer tour coming with 14 stadium dates that will feature a wealth of rotating acts, including Keith Urban, LeAnn Rimes, Gary Allan, Big & Rich and Luke Bryan, among others. And Brad Paisley plans to hit the road with Chuck Wicks, Jewel and "Dancing With The Stars" celebrity Julianne Hough.

Two all-male lineups are also in the works for the season. Charlie Daniels takes his Volunteer Jam on tour, featuring two acts with plenty of Southern rock in the mix: .38 Special (which includes Donnie Van Zant, of the country duo Van Zant) and Shooter Jennings.

The Vol Jam has quite the history; Charlie started hosting Southern rock festivals under that banner in the mid-1970s, and they became a legendary annual event.

"We had such a good time, we decided we should do this once in a while," Charlie says.

Also on tap is the Honky Tonk Tailgate Party 2008. Mark Wills, who hosts the GAC series The Year, headlines the dates with Buddy Jewell, Trent Willmon and Ray Scott, a singer-songwriter who authored the Clay Walker hit "A Few Questions."