Hilary is well known to fans of Cornish music at home and abroad, having been a founder member of much loved band Gwaryoryon and the ground-breaking Sowena. She is at the forefront of the revival of interest in the clarinet as a traditional instrument in Cornwall, where it was popular in the 19th and early 20th centuries. Hilary is now one of the leading authorities on Cornish traditional music and is currently producing Cornish music and singing resources through her Fenten project. She also co-founded the Cornish music promotion company Cumpas Ltd, and in 2004 became a bard of the Cornish Gorsedh.