Many social media users criticized the performance as "disastrous" and a "train wreck", prompting the singer to explain the snafu in a post of her own.
The track finally came to an end with her saying sarcastically: "That was. wonderful".
Fans have been uploading clips of themselves singing to Mariah Carey songs off-key. "I'm going to say let the audience sing".
Carey headlined the festivities in New York's Times Square, where about a million partygoers jammed the streets to usher in the new year. Her camp says they complained over and over, but no resolution came of it. She appeared flustered and on the verge of tears as she declined to sing some lines of her songs.
"We can't hear", she told the crowd.
This left the multi-platinum recording artist upset once again as she stopped singing.
She never found one.
At the end of her performance she abruptly walked off stage and signed off with: "It just don't get any better". "Put these monitors on please!"
"We didn't have a check for this song. we're missing some of the vocals, but it is what it is".
Others compared her to infamous lip-syncers like Ashley Simpson and 1980s pop duo Milli Vanilli.
"No matter what Mariah does, the crowd absolutely loves it", Seacrest said.
Shortly after the performance, Carey sent out a tweet recognizing what a mess the whole thing was while also maintaining a sense of humor: "Shit happens". She said no more of the incident, but she admitted that she's expecting to make more headlines this year.