The list of country stars for Toby Keith’s sold out Twister Relief Concert on July 6th keeps growing.

Carrie Underwood has officially been added along with Toby, Garth Brooks, Trisha Yearwood, Willie Nelson, Sammy Hagar, Ronnie Dunn, Mel Tillis and John Anderson. More stars are expected to be announced soon.

Because she’s already got a previous commitment to perform on the Grand Ole Opry that same night, Carrie will appear via satellite from the Opry stage.

Proceeds from the concert will go to the United Way of Central Oklahoma May Tornadoes Relief Fund.