Book excerpt: Where Heaven and Earth Meet is a Festschrift in honor of Daniel F. Callahan, Professor of History at the University of Delaware. It is an interdisciplinary collection that celebrates and advances research in his principal scholarly interests. One central focus is on the writings of Ademar of Chabannes and what they reveal about heresy, music, warfare, and the Peace of God in the early Middle Ages. Another is on Western religious history (ecclesiastical houses, hagiography, and papal writings), and the collection is rounded out by studies of early Islamic Jerusalem as well as Arabic numismatics. Contributing authors include Professor Callahan’s former classmates, graduate students, colleagues and admirers of his research. The collection will be of interest to researchers in art history, history, musicology, and religion. Contributors are: Bernard S. Bachrach, Daniel F. Callahan, Lawrence G. Duggan, Michael Frassetto, Matthew Gabriele, James Grier, John D. Hosler, Anna Trumbore Jones, Lawrence Nees, Richard R. Ring, Jane T. Schulenburg