On the Nature of Transmission and Change in Trope Repertories *
Recent reinterpretations of the evidence on the early transmission of Gregorian chant point to a larger role for written sources than had previously been thought. Evidence for the trope repertories—the ordered transmission of entire trope series for a number of feasts over a considerable period of time—points to similar conclusions. Variations in trope series from one region to another point to the existence of general regional traditions. Since tropes did not possess the authority of Gregorian chant itself, they were 201acclimatized in each region in order to make them conform to local traditions, which seem to have their roots in the chant sung in each locality before the adoption of the Roman liturgy and Gregorian chant.
The nature of the acclimatizations, both textual and musical, indicate that the tropes were often received in written form and then changed and manipulated in ways that in themselves suggest dependency upon a written text and music.