CAJHA : computer aided jazz harmony analysis

Abstract

Jazz performance requires the ability of musicians to improvise new melodies over a given tune structure and embellish its harmonies in real-time. In order to be able to achieve this creative goal, musicians familiarise themselves with jazz tunes a priori by performing analysis of their inherent harmony structures, whereby they consider each chord's harmonic function in a chord sequence so as to obtain insight into the composer's creation. Since Western music harmony principles have been historically developed using mathematical principles, it is possible to create a logical model of the musical concepts necessary for jazz harmony analysis. Whether for use in a musician's jazz performance preparation or for employment in a novice musician's didactic training, the jazz harmony analysis problem presents itself as one that is ideally suited to computer treatment. This experimental study is concerned with the development of a reusable and extendable jazz harmony analysis platform by modelling the necessary musical concepts and the relationships amongst them in the object-oriented paradigm, and providing algorithms that can operate upon these concepts and relationships to perform various types of jazz harmony analysis. This study is also concerned with the development of a jazz chord spelling grammar and a corresponding parser which can build musical objects from user input in the form of chords in use in jazz. Finally, this study involves the development of an interface which allows the user to interact with the computer in selecting analysis solutions from those automatically generated to contribute to a final analysis solution that is a hybrid of machine suggestions and user selections, thereby bringing the computer to the human's assistance but not giving it final decision rights, respecting the human's final say in the art. The developed system is tested using three typical jazz standards and the outcome is deemed satisfactory.