Zipf's Law and the Evolution of Musical Lyrics: A Comparative Analysis of the 1960s, 1990s and the Present

Abstract Song lyrics offer valuable insights into the social and cultural contexts of each period, reflecting the themes and concerns of the time. This study applies Zipf's law to analyse the evolution of lyrical complexity using data from the Billboard Year-End Hot 100 singles during three distinct periods: 1959–1969, 1991–1999, and 2016–2024. To assess repetitiveness trends, the analysis employs the Zipf coefficient (α̂) and the coefficient of determination (R²) derived from log-log models. The findings reveal lower repetitiveness in both the 1960s and the contemporary period, according to the value of the coefficient α, with higher degree observed in the 1990s. Contrary to the initial hypothesis, the results suggest that the digital age has not contributed to the simplification of lyrics. This research underscores the influence of technology on music production and opens avenues for further exploration into its impact on other forms of art and culture.