Bach, like Shakespeare, is known largely by his works, exceptional in quantity as well as quality, and only a few original documents convey any idea of his life and character. Peter Williams's 2003 look at Bach's biography asks many questions about the so-called evidence. What was he like as a young man, as a father, as an ageing church servant? What were his preoccupations? What music did he know and how did he compose and perform such an amazing...