Rhythmic Patterns in Ragtime and Jazz

Abstract

This paper presents a corpus-based study on rhythmic patterns in ragtime and jazz. Ragtime and jazz are related genres, but there are open questions on what specifies the two genres. Earlier studies revealed that variations of a particular syncopation pattern, referred to as 121, are among the most frequently used patterns in ragtime music. Literature in musicology states that another pattern, clave, is often heard in jazz, particularly in songs composed before 1945. Using computational tools, this paper tests three hypotheses on the occurrence of 121 syncopation and clave patterns in ragtime and jazz. For this purpose, we introduce a new data set of 252 jazz MIDI files with annotated melody and metadata. We also use the RAG-collection, which consists of around 11000 ragtime MIDI files and metadata. Our analysis shows that syncopation patterns are significantly more frequent in the melody of ragtime pieces than in jazz. Clave on the other hand is found significantly more in jazz melodies than in ragtime. Our findings show that the frequencies of rhythmic patterns differ significantly between music genres, and thus can be used as a feature in automatic genre classification.