While Blake Shelton helped host the televised relief concert Healing in the Heartland shortly after the tornado hit (which raised over $6 million), Keith and fellow Oklahoma resident Garth Brooks felt, for them, that it was too soon (Shelton's concert took place May 29).

"I talked to Garth and he said, 'It's too soon for me. Are you doing this concert?' And I said, 'No, I'm not,'" Keith explained in a recent interview with Radio.com. Brooks told him, though, that when he was ready to do a concert, to let him know.

"As soon as I knew he was going to participate with whatever I came up with, then I called Willie [Nelson] and Ronnie Dunn and Sammy Hagar, and from there it started growing," Keith said. "They'll take all the money we can give them."

Dubbed the Oklahoma Twister Relief Concert, the event takes place Saturday, July 6 in Norman, Okla., and according to Keith, "it's a monster. A whole football stadium got sold out in a matter of minutes. It's wonderful to know that those people care and want to come in and do this for my hometown. I'm very blessed."

Since the initial lineup was announced, additional artists have stepped up to show their support. These include another Oklahoma native, Carrie Underwood, who will perform via satellite.