Actor Derek Jacobi grew up in Walthamstow, where his parents ran a market stall. But a clue in his mother's family tree hints at a more colourful past - his great-grandmother's name was Salome Laplain. Armed with this tantalising detail, Derek discovers that, far from being from humble roots as he had thought, he is in fact descended from a wealthy French Huguenot fleeing religious persecution in France - who had connections to Protestant royalty on this side of the channel.

Choirmaster Gareth Malone's passion for singing is in his blood - his parents met singing in musicals, and Gareth grew up surrounded by music. But he wants to know how far back his 'ta-dah' gene goes, and sets off to find out more.

His investigations into his mother's side of the family take him to London's West End, where he finds his great-great-grandfather, a star of musical comedy, performing for the king, George V. But it doesn't stop there - two more generations back and Gareth's journey takes him to the heyday of music hall and a theatre impresario in Dublin.