The fugue of the mature Baroque was the final flowering of Renaissance and Baroque polyphony. While most composers of Bach's generation had turned to other musical forms, Bach himself continued to write in "older" styles, and was to become the unchallenged master of the fugue. Die Kunst der Fuge was written during the last years of his life, and was being prepared for publication at the time of his death.
Although it seemed to arrive out of nowhere in the early '90s, ambient music actually has a long and varied history, leading back to Brian Eno and Kraftwerk's electronic experiments in the 1970s, right up to Aphex Twin's textural techno soundscapes. As an introduction and history lesson, the two-disc A Brief History of Ambient Music can't be beat; it shows that the ambient-techno trend has roots that most fans wouldn't even realize existed.