Keith Urban's 'Escape Together World Tour' kicks off tonight (May 7) at the Mohegan Sun in Uncasville, Connecticut, but there's been a last-minute change in the lineup. Jason Aldean will take the stage as opening act for tonight's show, replacing Sugarland, whose lead singer Jennifer Nettles has been put on vocal rest for 10 days. Tomorrow night's Mohegan Sun show will feature Little Big Town in the opening slot, with announcements about supporting acts for future shows expected soon.

According to Sugarland's website, Jennifer received doctor's orders for vocal rest due to a viral tonsil condition.

As the time to 'Escape Together' draws closer, Keith arrived in Uncasville on Tuesday, and almost immediately hit the Mohegan Sun stage for a full run-through of his show. He says opening night is usually "a pretty good mix of calm and anxiety. But the minute that I see everyone's faces and they're singing, it's all good. I'm looking forward to getting this all started."

Click here for a full list of Keith Urban tour dates.