Mariah Carey Rings In 2017 With Painful Lip Sync Fail On Live TV | The Huffington Post
This is worse than I thought it would be. Her monitors weren't working. It looks like she took one earpiece out to try and hear the music.
You can hear the high notes that were left in the backing track so she doesn't have to hit them. There had to be a soundcheck for this, she just didn't show up.