Rascal Flatts have canceled Thursday night’s (July 10) concert in Oklahoma City, as Gary LeVox is unable to sing.

The band made the announcement on Wednesday night, saying an undisclosed illness is affecting the lead singer’s vocal chords. Sheryl Crow and Gloriana were the opening acts scheduled for the date at OKC Downtown Airpark. No makeup date was announced. Fans who bought tickets with a credit card will have their money refunded within seven business days. All others should contact Stubwire at 877-960-7882.

Thursday’s date was to be the first of four straight for the country trio. Their next scheduled day off isn’t until July 14. As of now, concerts planned for Austin and Dallas are still on schedule.

Later this summer, Rascal Flatts will be on high alert, as Joe Don Rooney’s wife Tiffany waits to have the couple’s third child. She’s due in late summer. The group released their new album, ‘Rewind,’ in May.

Rascal Flatts Perform 'Rewind' Like You've Never Seen Them Before