Kelly Clarkson's highly anticipated Las Vegas residency opening was postponed hours before showtime because the singer needs vocal rest after demanding preparations.

There has to be some repercussion. Something for the people that spent thousands to get there,” one upset fan wrote via social media.

The "Since U Been Gone" singer announced that she has postponed the first two shows of her planned Studio Sessions residency at the Colosseum at Caesars Palace on Friday.