A String in the Harp by Nancy BondMargaret K. McElderry Books, 1984 (originally 1976)

A time-travelling magical book, set in Wales, full of a sense of place and a sense of history and altogether pleasing because of that. At first, I wasn’t sure if I could get past the sometimes stiff dialogue, but the story soon grabbed my attention, as did the landscape, the sea and the rivers and the hills and the farmhouses.