Quartet become singing musketeers
1 August 2013 Last updated at 11:15 BST
Barbershopera are an a cappella quartet with fans across the globe.
They have recently returned from five sell-out gigs in South Korea and are now bringing their take on The Three Musketeers on a tour of the UK.
Peter Sorel Cameron, Laura Darton, Harry Stone and Russell Walker, who make up Barbershopera warmed up for their time on the road with a quick BBC Breakfast sing song...