A tree diagram that has demonstrated that live musical performances bear a “striking resemblance” to grouping analyses of tree diagrams. It is derived by plotting the peaks in putput of low-pass filters and “looking for zero crossings in the second derivative of the filter output.” If the peaks are plotted “across all the filters in a multi scale assembly, a representation of rhythmic events at a number of levels, and the grouping relationships between events” creates the rhythmograph.
One advantage of the rhythmograh is that it is based on “energy integration?,” meaning that it is sensitive to changes in acoustics that are related to the integrated energy level. These factors include: note duration, pitch?, intensity?, and even timbre and vibrato?,” meaning that written notes and the “expressive treatment that it receives in performance” are treated equally. (Clarke, 480)