X Factor contestant Relley Clarke has compared auditioning in front of Gary Barlow with being sent to the teacher's office.
The 23-year-old singer - who has been put through to the judge's houses round by girls' mentor Nicole Scherzinger - said that appearing before the Take That singer is a terrifying experience.
Clarke said: "No one could take over from Simon (Cowell), but Gary is a perfectionist, so he's always listening out for bum notes, vocals.
"It's quite nerve-wracking singing in front of Gary at times, he reminds me of a school teacher. It's like going to the teacher's office and you go 'Oh, what have I done now?'
"You can always tell if you've done something wrong - just look at Gary.
"But he's very professional so I rate him for that."
She also revealed former Pussycat Doll Scherzinger was a really fun judge.
Clarke said: "Nicole is lovely, she's stylish, she's hot, she's fierce. She's the best mentor for the girls.
"She's very ballsy. When it comes down to the crunch and it comes down to business, everyone knows what time it is and she lets us all know that she's not playing.
"But she has got a fun side and she's a bundle of joy.
"She's very witty, and I think the girls all really like that and we all connect because of that."