Kelly Clarkson has cancelled a performance at the Band Together Texas benefit concert in the wake of her ex-husband Brandon Blackstock's death.

Kelly Clarkson's ex-husband Brandon Blackstock's death certificate says seizures were a significant contributing factor in his Aug. 7 death.

Certified by the Butte-Silver Bow County Clerk and Recorder’s office in Butte, Montana, on Wednesday, Aug. 13, the death certificate verified that Blackstock died at 11:13 a.m. at his home in Butte on Thursday, Aug. 7, at the age of 48.