Watch The Saturdays's acoustic cover of Justin Bieber's 'Baby'

The Saturdays have performed a cover of one of the biggest singles of the year, Justin Bieber's 'Baby'. The verdict? We actually think it's pretty good.

But where's Mollie and who's that guy on the left we hear you ask? Well fear not Saturdays fans; Mollie was off sick when the girls were performing this, so don't worry, that guitarist guy has not joined the band.

Check the performance out and tell us what you think below: