What has happened to Mariah Carey’s voice? Singer's vocals are shockingly off in awkward Christmas performance

(This video is a stripped back version, not featuring the music - just the vocals)

Ummm who is that lady and what has she done with Mariah Carey?

The pop singer sounded nothing, and when we say nothing we mean nothing, like her former self when she helped switch on the lights at the Rockefeller Centre yesterday by singing All I Want For Christmas.

After being forced to perform live after missing her pre-recording the 44-year-oldgave an excruciating performance.

Her voice cracks, she misses pretty much all the notes and she looks, well pretty uncomfortable.

We don’t get it – she’s performed that song so many times before and for many of us her singing is Christmas. What is going on Mariah?