Niels Pfeffer (University of Tübingen) works with MPM to analyse piano rolls. In doing so it is possible to derive very interesting details on the roll production processes. A separate website is in preparation to present the approach and results. Recently, Music Performance Markup (MPM) has been presented as a format for encoding musical interpretation. Formally, MPM introduces elements that allows to describe the transformations necessary for turning a given score, encoded e.g. in MEI, into an actual performance. These transformations can describe, between which two points a ritardando takes place and which exact shape it has, how certain notes are articulated, how the dynamics change within a given range, and much more. MPM also provides elements to represent imprecision in both timing and dynamics, which could be used to show uncertainties inherent to piano rolls. Using an alignment of a digitized piano roll with a digital encoded musical score, it is possible to (semi-)automatically generate MPM.  The created MPM opens up a potential reaching far beyond an annotated reconstruction of a performance. We can easily experiment with the MPM. Thus it is possible to omit or even to exaggerate several parameters – e.g. to play back the performance with the same agogics but without any arpeggiations, or without any tempo modifications but exaggerating the given dynamics. It is furthermore possible to apply the same interpretation to a different musical structure, e.g. to a harmonic reduction, which opens a wide space for artistic research.