Johann David Heinichen was (along with Johann Mattheson, Johann Gottfried Walther, Kirnberger, and J. J. Fux) one the important music theorists of the late Baroque era. His treatise primarily deals with figured-bass theory, but also reflects a summary of music theory mixed with new ideas of the Dresden school. Professor Buelow's book wisely selects important portions in translation and summarizes some of the parts of lesser interest and importance. Anyone doing research in Baroque music theory should own this because it is a treasure trove of material for theorists. It is a scholarly volume that will not appeal to a general audience.