ABSTRACT
Gregorian chants having international diffusion are preserved in hundreds of sources ranging from the tenth century onward. It is necessary to collate large numbers of these in order to demonstrate the degrees of faithfulness and change in the transmission of the repertoire and thus construct a history of chant. MS inventories are of inestimable aid in facilitating such editorial comparisons. As demonstrated by means of selected examples, comparative editions help us to interpret illusory notations and to comprehend theoretical writings dealing with chant.
