ABSTRACT
The trope repertories may be seen as waves, arriving on shore after most other aspects of liturgical tradition had been laid down. The relationships between sources according to their trope repertories often contradict the evidence of other aspects of liturgical tradition. Some obvious examples of this may be found in North Italian sources. Two maps are given which enclose North Italian towns from which tropers survive in boundaries of various types. In the upper map, a dotted line shows that the surviving collections of sequences from Pavia, Mantua, Nonantola and Forlimpopoli are dominated by German compositions, whereas the collection from Monza is more French in character. As attempted with the Pavia and Balerna tropers, it will be possible to give to the computer for analysis not simply a number denominating a particular trope but also a simple label indicating its likely provenance.
