Automatic analysis of global music recordings suggests scale tuning universals

Abstract

The structure of musical scales has been proposed to reflect universal acoustic principles based on simple integer ratios. However, some studying tuning in small samples of non-Western cultures have argued that such ratios are not universal but specific to Western music. To address this debate, we applied an algorithm that could automatically analyze and cross-culturally compare scale tunings to a global sample of 50 music recordings, including both instrumental and vocal pieces. Although we found great cross-cultural diversity in most scale degrees, these preliminary results also suggest a strong tendency to include the simplest possible integer ratio within the octave (perfect fifth, 3:2 ratio, ~700 cents) in both Western and non-Western cultures. This suggests that cultural diversity in musical scales is not without limit, but is constrained by universal psycho-acoustic principles that may shed light on the evolution of human music.

Universal and Non-universal Features of Musical Pitch Perception Revealed by Singing

“…However, we also cannot exclude the possibility (suggested by the original authors) that there is some perceptual equivalence at birth that fades if a listener does not experience the appropriate musical system. Our results also do not speak to the reasons for the worldwide prevalence of the octave in musical systems [33]. One possibility is that octaves are easy to produce reliably on simple instruments and thus form an ''attractor point'' for the evolution of scale systems.…”

“…The origins of musical pitch remain unclear in part because pitch representations have rarely been studied experimentally in non-Western cultures [27][28][29][30][31][32]. Cross-cultural observations have largely been limited to ethnomusicological studies of the structure of musical systems around the world or the analysis of recorded material [33]. There are many examples of logarithmic scales in other cultures [34][35][36] and of pitches separated by an octave being notated in the same way [37,38].…”

Automatic comparison of global children’s and adult songs supports a sensorimotor hypothesis for the origin of musical scales

“…Comparison of normalized scale analysis Finally, the scale normalization to the tonal center (= tuning into same key) was performed to verify whether there is a tendency toward common intervals relative to the tonal centre of the scales. In order to compare scales across cultures, we attempted to normalize each scale by tuning the final pitch class to be 0 cents, following the method attempted in our previous study [7]. When the ending note is not detectable because of fade out or excerpts in a song, we instead normalized to the most frequent note as a tonal center (recent analyses [3] suggest that there is little difference between these two methods, leading us to propose consistently normalizing to the most frequent note in the future).…”

Automatic comparison of human music, speech, and bird song suggests uniqueness of human scales

“…Previously, we used automated scale analysis software to demonstrate a strong cross-cultural tendency for human music to use scales containing pitches separated by intervals that approximate simple integers, particularly a perfect 5th (e.g., 700 cents, ~ 3:2 frequency ratio) [8]. If perfect fifths also predominate in bird song or human speech as well as human music, then they are likely a consequence of perceptual/motor constraints, whereas if they are specific to human music, this suggests that they could be an adaptation specifically for human music [23].…”