Measuring the evolution of contemporary western popular music

TL;DR

This study analyzes the structural patterns and evolution of contemporary western popular music over fifty years, revealing both stability and significant trends in pitch, timbre, and loudness that influence perceived novelty.

Contribution

It uncovers stable musical regularities and identifies key trends in pitch, timbre, and loudness, providing a formal understanding of musical evolution.

Findings

Stable patterns in pitch, timbre, and loudness over fifty years

Trends towards restricted pitch transitions and homogenized timbre

Increasing loudness levels in popular music

Abstract

Popular music is a key cultural expression that has captured listeners' attention for ages. Many of the structural regularities underlying musical discourse are yet to be discovered and, accordingly, their historical evolution remains formally unknown. Here we unveil a number of patterns and metrics characterizing the generic usage of primary musical facets such as pitch, timbre, and loudness in contemporary western popular music. Many of these patterns and metrics have been consistently stable for a period of more than fifty years, thus pointing towards a great degree of conventionalism. Nonetheless, we prove important changes or trends related to the restriction of pitch transitions, the homogenization of the timbral palette, and the growing loudness levels. This suggests that our perception of the new would be rooted on these changing characteristics. Hence, an old tune could perfectly sound novel and fashionable, provided that it consisted of common harmonic progressions, changed the instrumentation, and increased the average loudness.