John Birchensha (c.1605-?1681) is chiefly remembered for the impression that his theories about music made on the mathematicians, natural philosophers and virtuosi of the Royal Society in the 1660s and 1670s, and for inventing a system that he claimed would enable even those without practical experience of music to learn to compose in a short time by means of 'a few easy, certain, and perfect Rules'-his most famous composition pupil being Samuel Pepys in 1662. His great aim was to publish a treatise on music in its philosophical, mathematical and practical aspects (which would have included a...