Bill is a specialist in performance of ancient harp music from Ireland, Scotland and Wales, and is one of very few players investigating these repertoires on medieval gut-strung harps, wire-strung clarsachs and Renaissance harps with buzzing bray pins. He is a contributor to the New Grove Dictionary of Music and Musicians, and serves on the committee of the Wire Branch of the Clarsach Society. He has been resident in Scotland for many years, where he teaches and works with Ardival Harps in Strathpeffer.

In Scotland, he performs with Canty, the Highland early music group Coronach and the duo The Art of Musick; he also performs further afield with the Belgian ensembles Quadrivium and Graindelavoix. Bill teaches community music classes through Fèis Rois and is a guest lecturer at the Royal Conservatoire of Scotland. As a teacher of historical harps, he is frequently invited to lead workshops in the UK, Europe and the USA, including regular appearances at the Edinburgh International Harp Festival.