ABSTRACT
I remember the day I got my first Liber Usualis. It was an ordinary fall afternoon in Andover, Massachusetts, in 1981.1 received a telephone call from a friend saying he could deliver what I had been waiting for. We arranged to meet. When he arrived with the package, looking both triumphant and a little sheepish, I learned that the book had been stolen, not by my friend but by an unidentified third party, a woman who had discovered a box of the precious Libri lying unattended in the basement of the church where she worked as organist. The anonymous thief, whom I would never be able to thank, managed to pilfer three of them before the authorities or her guilt caught up with her—I never knew which. I simply felt lucky to have benefited from her sin.
