Source-linked AI summary
Measuring the evolution of contemporary western popular music
Joan Serrà, Álvaro Corral, Marián Boguñá, Martín Haro, Josep Lluis Arcos
TL;DR
The paper addresses the limited formal knowledge of structural regularities and their historical evolution in contemporary western popular music. It analyzes musical codewords and related patterns in a large-scale study, finding stable metrics over more than 50 years alongside less varied pitch transitions, timbral homogenization, and louder levels.
Problem
Many structural regularities underlying musical discourse and their historical evolution remain formally unknown.
Method
The study uses large-scale analysis of musical codewords and network metrics to characterize pitch, timbre, and loudness in popular music.
Results
Patterns and metrics remain stable for more than 50 years, while pitch transitions become less varied, timbres more homogeneous, and loudness levels higher.
Takeaways & Limitations
The findings suggest that perceived musical novelty is rooted in changing pitch, timbral, and loudness characteristics rather than broad overall trends.
Takeaways & Limitations
The codeword representation does not account for discourse syntax, and some discovered paths may encounter this limitation.
Abstract
from arXiv · showhide
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.
Introduction
The paper examines long-term structural patterns in contemporary western popular music using large-scale, objective analysis of pitch, timbre, and loudness. It finds both persistent conventionalism and important trends toward simpler pitch transitions, a more homogeneous timbral palette, and higher loudness.
- Long-term variations in popular music remain formally underexplored, despite their relevance to understanding musical organization, structure, dynamics, and novelty.
- Current music-information technologies enable objective, empirical, quantitative, and large-scale analyses of musical patterns.
- The study analyzes 464,411 recordings from 1955 to 2010 spanning rock, pop, hip hop, metal, and electronic music.The recordings include year annotations and audio descriptions of loudness, pitch, and timbre.
- Loudness, pitch, and timbre provide complementary descriptions of music at beat-level temporal resolution.Loudness relates to perceived amplitude, pitch to harmonic content, and timbre to sound color, texture, or tone quality.
- Statistical-physics and complex-network tools reveal patterns and metrics whose usage remains stable for more than 50 years.This long-term stability points toward substantial conventionalism in the creation and production of contemporary western popular music.
- Three major trends are restricted pitch transitions, homogenized timbral usage, and growing average loudness levels.The paper links these changing characteristics to perceptions of novelty: simpler pitch sequences, novel timbral mixtures, and louder recordings may make older tunes sound fashionable.
Results
The analysis identifies stable statistical regularities in musical vocabularies and transition networks across decades, alongside trends toward restricted pitch transitions, timbral homogenization, and louder recordings.
- Pitch: Pitch codeword frequencies follow a stable power law across more than 50 years, with exponent β averaging 2.18±0.06.The regression of β over year is negligible within statistical significance.
- Transition networks: Transition networks are sparse, quantitatively capturing music’s balance between predictability and surprise while leaving many composition paths available.Sparse networks mean only a limited number of codeword transitions is possible, supporting recognition and enjoyment while retaining paths for originality.
- Pitch transitions: Pitch transition networks become progressively more restricted, with fewer transition options and more defined paths between codewords.Small-worldness decreases as average path length rises from 2.9 to 3.2 and clustering falls from 0.65 to 0.45.
- Timbre: Timbre codeword distributions become more concentrated over time, as β decreases toward 4, indicating homogenization of the global timbral palette.Rank correlations average 0.57±0.15, which can attenuate the perceived homogeneity because formerly frequent timbres may later become infrequent.
- Loudness: Loudness medians increase from −22 dBFS to −13 dBFS at 0.13 dB/year, while absolute dynamic variability remains around 9.5 dB.The dynamic-range regression is not statistically significant, indicating conserved absolute variability despite increasing loudness.
- Loudness transitions: Loudness transition networks retain stable topology, with median degree between 13 and 14, clustering averaging 0.59±0.02, and no extreme loudness transitions.Their stable metrics imply that transition topology is maintained despite the race toward louder music.
Discussion
The analysis finds strong conventionalism alongside historical changes in pitch transitions, timbre, and loudness. These changes are linked to how listeners may perceive older music as contemporary.
- Conventionalism: More than fifty years of popular music show substantial conventionalism, with stable global patterns and no considerable overall change.Pitch codeword frequencies retain the same power-law exponent and fitting parameters, while several network metrics remain immutable.
- Pitch: Pitch codeword frequency rankings are practically identical across the period, despite clear changes in some pitch-network metrics.The historical trends point toward less variety in pitch transitions.
- Timbre and loudness: Timbre frequencies follow a power law, while loudness frequencies follow a reversed log-normal distribution.The parameters of these distributions nevertheless change over time.
- Historical trends: The observed trends indicate less variety in pitch transitions, homogenization of the timbral palette, and louder volumes with potentially poorer dynamics.Frequent timbres become more frequent as the global palette homogenizes.
- Perceived novelty: The paper proposes that perceived novelty is rooted in simpler pitch sequences, novel timbral mixtures, and louder volumes enabled by modern recording techniques.It conjectures that an old popular piece could sound novel by following these guidelines.
- Evidence and scope: The study replaces earlier subjective or non-systematic conjectures with formal, quantitative, systematic analysis of a large-scale music collection.It also encourages historical databases for studying broader musical transitions and more subtle genre- or artist-level evolution.