“All I Ask,” it was clear that something was wrong.

A clanking sound could be heard in the background as she sang, her microphone cut out briefly and Adele’s voice didn’t have its usual punch. The singer looked distracted, flashing irritated looks as she powered through the song, backed only by a piano and bathed in a lone spotlight.

Fans, who anticipated another killer performance, were confused. Adele, sounding … flat?

The singer offered an explanation afterward on Twitter, saying, “The piano mics fell on to the piano strings, that’s what the guitar sound was. It made it sound out of tune. S— happens.

 

Don’t feel too bad for Adele, though. The singer, who wasn’t eligible for Grammys on Monday night because her album came out too late in the year, said the mishap led her to treat herself after the show to In-N-Out Burger, so “maybe it was worth it.