Bistate reduction and comparison of drum patterns

Abstract

This paper develops the hypothesis that symbolic drum patterns can be represented in a reduced form as a simple oscillation between two states, a Low state (commonly associated with kick drum events) and a High state (often associated with either snare drum or high hat). Both an onset time and an accent time is associated to each state. The systematic inference of the reduced form is formal-ized. This enables the specification of a rhythmic struc-tural similarity measure on drum patterns, where reduced patterns are compared through alignment. The two-state representation allows a low computational cost alignment, once the complex topological formalization is fully taken into account. A comparison with the Hamming distance, as well as similarity ratings collected from listeners on a drum loop dataset, indicates that the bistate reduction enables to convey subtle aspects that goes beyond surface-level comparison of rhythmic textures.