Bach's Changing World is a study of popular culture in the community in which Bach spent the last, the longest, and the most productive part of his life: the Leipzig middle-class. The Leipzig middle-class evolved with the cooperation and gratitude of an extravagant, greedy, and disinterested absolutist ruler. Bach's Changing World documents how this community and other German communities responded toa variety of religious, social, and political demands that emerged during the years of the composer's lifetime. An accepted, admired, and trusted member of this community, as evidenced by the commissions he received for secular celebrations from royalty and members of the middle-class alike -- in addition to functioning as church composer -- Bach shared its values. Contributors: Carol K. Baron, Susan H. Gillespie, Katherine Goodman, Joyce L. Irwin, Tanya Kevorkian, Ulrich Siegele, John Van Cleve, and Ruben Weltsch. Carol K. Baron is Fellow for Life in the Department of Music at Stony Brook University, where she was co-founder and administrator of the Bach Aria Festival and Institute.