A technical look at swing rhythm in music

We investigate swing rhythm in music using computer analysis techniques. Swing is not a genre of music, rather a style of performance. The same musical piece (data) can be played in swing or straight time. Musical notes and structure are identical in both performances, but the notes temporal patterns have slight, significant differences between straight and swing performances. We demonstrate a technical approach analyzing these differences, and show examples of several styles of swing: American Swing, Brasilian Samba, Jamaican Reggae. Prior research into swing rhythm discovered swing ratio representing the temporal variation of the music as performed compared to the music as written. Our work shows that in some cases swing ratio is inadequate to properly model the real patterns of temporal variation. We have extracted details showing swing exists hierarchically, i.e., the patterns of temporal variation played at one time scale may differ from the types of patterns of temporal variation played at a slower or faster time scale. We also show examples of different instruments playing swing differently from each other, locking together at certain canonical time locations that represent standard counting and subdivision of the musical meter. This latter phenomenon has been previously investigated as ensemble swing.