After enormous crowds packed into Oxford, Mississippi, to see country star Morgan Wallen in concert, the singer suddenly announced he would be unable to sing Sunday after the opening acts performed.

Wallen had performed the night before at the University of Mississippi’s Vaught-Hemingway Stadium and was scheduled for a second performance Sunday night.

Wallen posted a statement to social media about the matter:

“After last night’s show I started losing my voice so I spent the day resting up, talking to my doctor and working through my vocal exercises trying to get better. I really thought I’d be able to take the stage and it kills me to deliver this so close to showtime, but my voice is shot and I am unable to sing.”

All tickets will be refunded at point of purchase. I am so sorry, I promise you guys I tried everything I could,” Wallen wrote.