Linguistic tone in Chinese rap: an interdisciplinary approach

This study, integrating linguistics, computer science, statistics, musicology, and cultural study, explores how the lexical tones of Mandarin Chinese interact with rap music. Building upon Dong, H. Y. (2015). Musicality meets tonality: A tonal congruence index (ITG) for Chinese vocal music. In H. Y. Tao et al. (Ed.), Proceedings of the 27th North American conference on Chinese linguistics (Vol. 2, pp. 322–339)., we develop an algorithm to compute the Tonal Congruence Index (ITG), measuring the extent to which tones are preserved in vocal music. Analysis of a dataset with over 8000 syllables from Mandarin Chinese rap songs shows that the tonal congruence is related to subgenres that have evolved over time: while tones are largely preserved in the earlier boom-bap style, tonal distortion occurs more frequently in recent trap music. Moreover, we find that the falling fourth tone in standard Mandarin accounts for 38% of line-ending syllables in the lyrics of 140 rap songs and further suggests that the pre-eminence of the fourth tone may be a generic feature of Mandarin Chinese rap, particularly in boom bap. In addition, Chinese rappers have increasingly utilised English words over time to achieve musical flow. Integrating analytic findings with qualitative interviews of five national award-winning Chinese rappers, we conclude that the restriction of linguistic tones in Mandarin Chinese rap has gradually weakened over time and that there is a decreasing correlation between tone and rap with the emergence of new rap styles such as mumble rap and melodic rap.