Lionel Richie has said that The Voice was an "eye-opening experience" for him because he realised he wouldn't be able to do what the contestants have done.
The legendary singer will serve as a mentor for Christina Aguilera's team on the second season, which currently airs Monday nights on NBC.
Speaking to social media correspondent Christina Milian, he said: "It was probably one of the most eye-opening experiences ever because I now know what I would not be able to take!
"It's incredible. I'm having trouble every day trying to get my confidence together to say, 'I think I'll try that, I think I'll go with this song today, I'm not sure'… then let's make it one step more difficult and surprise you with a celebrity!"
