Sian James, Mim Twm Llai, Crasdant, Gwenno Saunders, Robin Huw Bowen, Pigyn Clust, Heather Jones, Neil Browning, Gwerinos, Rachel, Carreg Lafar, Plethyn, Bob Delyn, Rhes Ganol, Meic Stevens & Ar Log perform on this unique collection of Welsh folk songs