Kelly Clarkson postponed the opening of her "Kelly Clarkson: Studio Sessions" residency at the Colosseum at Caesars Palace after announcing less than two hours before Friday’s curtain that intense rehearsals had strained her voice. The decision affects the first two shows, scheduled for July 4 and 5. In a statement, the 43-year-old singer said preparing the production had “taken a toll on my voice” and that resting now would prevent serious damage. Caesars Palace described the new production as an “intimate” concert series and voiced confidence it will debut once Clarkson recovers. The 18-date engagement is slated to run on select weekends through Nov. 15, with the opener now expected on July 11. Ticketmaster told customers they may either keep their tickets for the rescheduled performances or request refunds.