A hierarchic diff algorith for collaborative music document editing.

We describe an application of hierarchic diff to the collaborative editing of tree-based music representations, using Zhang and Shasha's tree edit distance algorithm as implemented within the XUDiff tool. The edit distance between two trees is the minimum number of edit operations necessary to transform one tree into the other. We consider common operations on the score tree—deleting, changing, and appending tree nodes—to derive a minimal edit sequence, known as an edit script, and we compare the performance of the widely used Longest Common Subsequence algorithm against our approach. We conclude by summarizing implications for the design of collaborative music document software systems.