The role of population size in folk tune complexity

Demography, particularly population size, plays a key role in cultural complexity. However, the relationship between population size and complexity appears to vary across domains: while studies of technology typically find a positive correlation, the opposite is true for language, and the role of population size in complexity in the arts remains to be established. Here, we investigate the relationship between population size and complexity in music using Irish folk session tunes as a case study. Using analyses of a large online folk tune dataset, we show that popular tunes played by larger communities of musicians have diversified into a greater number of different versions which encompass more variation in melodic complexity compared with less popular tunes. However, popular tunes also tend to be intermediate in melodic complexity and variation in complexity is lower than expected given the increased number of tune versions. We also find that user preferences for individual tune versio...