You could check their singing skills for yourself by subscribing to their YouTube account (ootboxford).
Their latest in date? A Shakira medley for charity.
Listen to Hips Don't Lie, Whenever Wherever, and Waka Waka, and donate to Helen&Douglas House, the world's first children hospice.
Learn more about the charity http://bitly.com/hdhouseootb and buy the single http://bit.ly/ootbcharityshakira on OOTB's website www.ootboxford.com
Here's the link to the video. I hope you enjoy it and check more of their performances (don't miss their Let It Snow flashmob in the London Underground).