La Roux worry no one will come to see them play.
Singer Elly Jackson was convinced the group - also consisting of Ben Langmaid - would be playing to an empty crowd at last year's Glastonbury Festival, despite their appearance at the world famous music event coming after their single 'Bulletproof' topped the UK charts.
Elly said: "Nobody could have convinced me that there was going to be anybody at that gig. I thought, 'Nobody knows who we are. Nobody's going to turn up, I'm going to look like an idiot.'
"And there were 10,000 people there."
She admits that she has felt this way before every performance, but insists it is a good outlook to have.
The singer added to The Independent newspaper: "I feel that if I always think the worst, I won't be disappointed."
Elly doesn't know if she will be able to emulate the success of hit singles 'Bulletproof' and 'In for the Kill' again because she doesn't know what makes a hit record.
She said: "The magic ingredients that turn a song into a successful single are very hard to pin down. The biggest single is not necessarily the nicest song on the record, or the one that makes you feel the best.
"There's just some mysterious element to it and contrary to popular belief, it's not about how catchy it is."