Spitta's monumental study of Johann Sebastian Bach is one of the great
classics of musicology. Since it was first published in 1873-1880, it
has remained the basic work on Bach and the foundation for later
research and study. It may never be superceded as the most ambitious
coverage of its subject, since Spitta combined a genius for historical
scholarship, great musical understanding and an incredible energy in
gathering source material that has seldom been matched.