Mariah Carey accidentally left her voice at home last night for NBC's annual Christmas broadcast.

During "All I Want for Christmas Is You," Mariah missed most of the high notes she's famous for.

Apparently, Mariah was supposed to pre-tape her segment Tuesday but blew off her scheduled time slot for a phone meeting with her divorce attorney. When she finally showed up, three hours late, NBC execs sent her home without filming and had her do it live last night instead.

She apologized on Twitter:

"Last night's situation was beyond my control. I apologize to all that showed up, you know that I would never want to disappoint you."