1 This is an extended version of a paper that appeared in the Proceedings of the 12th International Conference on Music Perception and Cognition (ICMPC), and 8th Triennial Conference of the European Society for the Cognitive Sciences of Music (ESCOM), in Thessaloniki, Greece, on July 2328, 2012, pp. 1001–1008, under the title: “The pairwise variability index as a tool in musical rhythm analysis.”