AIRS 1st Annual Meeting: 2009

Title: Comparison of rhythm in musical scores and performances as measured with the
pairwise variability index
Authors: Marju Raju (Estonian Academy of Music and Theatre), Eva Liina Asu (Institute of
Estonian and General Linguistics), Jaan Ross (University of Tartu, Estonia)

Abstract

This paper tests two hypotheses: (1) that the nPVI values computed on the basis of recorded
performances may be higher than the nPVI values computed for the same works as musical
scores, and (2) that the musical nPVI values for different composers may vary substantially
within one culture even within a short time-span. In Experiment 1, samples from the works of
two Estonian composers, Mart Saar (1882-1963) and Eduard Tubin (1905-1982), were used for
calculation of nPVI on the basis of both scores and performances. nPVI values for performed
music were systematically higher than those for scores but the differences were not statistically
significant. In Experiment 2, larger corpora of scores by Saar, Tubin, and Veljo Tormis (born
1930) were analyzed. Solo parts in songs by Tormis had significantly lower nPVI values than
those in songs by Saar and Tubin. Our results show that calculation of nPVI values in music
may rely either on a score or on a performance, the results being not significantly different from
each other. The results also show that there may be significant differences in rhythmic contrast
between the works of composers from one culture created only a few decades apart, and that
nPVI values may not only increase but also decrease for compositions created later in time.