The Graduale Synopticum project is an especially significant data source for researching medieval chants by presenting early versions of these in a synoptic view. With a re-digitized, computer-readable version of the melodies, which were obtained from purely graphical synopses, we examine the variants of the melodies using digital methods.
For this purpose, we develop a generative evolutionary model that allows us to reconstruct a phylogenetic tree, illustrating the relationships of variations within and between the manuscripts vividly. This model enables us not only to trace a possible historical development but also to simulate how the chants might have changed and how the relationships of similarities within individual manuscripts, as well as between different manuscripts, have emerged.