Mariah Carey performed her signature holiday favourite "All I Want for Christmas Is You" at Rockefeller Center in New York Wednesday night, and you might say it did not go well.

The 44-year-old songstress struggled, strained and flat out missed several notes, and while it may not have been the worst singing performance of all time, it was a far cry from the Mariah that many of her fans remember.

Carey started out fine, offering up the usual vocal gymnastics she's famous for. But things seemed to fall apart around 38 seconds in, when her voice goes flat during a run of falsetto notes.

Almost every falsetto attempt misses the mark, and as the song goes on, Carey's voice appears to become more strained.

For the most part, Carey's vocal stumbles get covered up by the hard work of her backup singers. But the flat notes at 3:20 are painful and that high note at 3:35... well, safe to say that was a bad idea.

 

Some Vine users have cobbled together all of Carey's worst notes from her isolated vocal track.

Carey had been due to pre-tape her performance on Tuesday evening, but missed her time slot – apparently after getting caught up in a phone meeting with her divorce attorney, according to TMZ.

NBC later decided to allow Carey to perform live on Wednesday's broadcast.

As expected, many on Twitter didn't hold back in lamenting Carey's performance.