After a short hesitation, her back-up orchestra stopped and began the song again. The problem was not immediately clear.
Adele was tearful at the end of the performance but had the clear support from the audience comprising her colleagues, who gave her a standing ovation, and from fans on social media.
Singer Charlie Puth tweeted:
I commend @Adele for starting over and making it right! Very very good.? Charlie Puth (@charlieputh) February 13, 2017
Last year, Adele did not start over but her voice went painfully out of key as she performed All I Ask. The Grammy organizers later revealed that the problem was caused when a microphone fell on the piano's strings. Explaining her situation, Adele had tweeted: "The piano mics fell on to the piano strings, that's what the guitar sound was. It made it sound out of tune. S**t happens." Adele also added that she was pacifying herself with a burger: "Because of it though I'm treating myself to an In-N-Out. So maybe it was worth it.
It was the second performance on Sunday night by Adele, who opened the awards gala by singing her mega-hit Hello.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)