Exploring phrase form structures. Pt.II: Monophonic jazz solos

In this explorative study, we investigate the phrasal structure of a set of 100 monophonic jazz solo taken from the WEIMAR JAZZ DATABASE. The main purpose was to see whether phrase form structure might lead to useful features for computational jazz solo analysis. To this end, we extracted basic statistical descriptors for phrases such as the number of notes, event density, total duration etc. Furthermore, we analysed the self-similarity of phrase sequences with regard to semitone intervals and duration classes and in combination. Phrase form structure can be characterized by coherence values and runlengths. As expected, form coherence values are generally very low with duration-based form coherence being higher than interval-based or combined form structure. John Coltrane was found to be an exceptional case with very high duration-based coherences. Furthermore, a global tendency to increase in event density (i. e., intensity) at the beginning of solos was observed.