Off the top of my head I think John Tams was heavily involved with the music in the stage version.

The books are a personal evocation of Flora Thompson's life in rural England at the beginning of the last century, in a similar vein to "Cider with Rosie". Music is not at the forefront of the books, but became so in the stage adaptations. I notice MMario's link has a further link to a previous Mudcat discussion, which I haven't checked out.