A few of my favorite “Bach books”
Music in the Castle of Heaven. A Portrait of Johann Sebastian Bach. John Eliot Gardiner. Penguin Books.
The New Bach Reader. A Life of Johann Sebastian Bach in Letters and Documents. Edited by Hans T. David and Arthur Mendel. Revised and Expanded by Christoph Wolff. Norton and Company.
The New Grove BACH FAMILY. Christoph Wolf. Norton and Company.
Glory and Honor. The Musical and Artistic Legacy of Johann Sebastian Bach. Gregory Wilbur. Cumberland House.
Johann Sebastian Bach. The Culmination of an Era. Karl Geiringer. Oxford University Press.
J.S. Bach. Albert Schweitzer. Dover Publications.
Johann Sebastian Bach. His Life in Pictures and Documents, with CD. Hans Conrad Fischer. Haenssler.