Several shows have already been rescheduled. Check the band’s itinerary for details. Existing dates through May 7 will remain as scheduled.

“We’re disappointed to be postponing these dates, but it’s a relief to know the source of the problems I’d been having with my voice,” Key said. “And it’s much better to confront it now than later when it could be far more serious. But we’ll be back on the road in June when we can give 100 percent. Our fans deserve nothing less.”