Virtual Gamelan Graz: Disclosing Implicit Musical Knowledge

Javanese gamelan music has been the subject of scholarly studies since the pioneering work of Jaap Kunst during the 1930s. While our understanding of the general principles guiding this classical genre has considerably improved over the last decades and in spite of a substantial body of treatises on theoretical issues by Javanese authors, several aspects remain to be investigated whose clarification relies on musical knowledge of local experts which is usually not verbalized. This is particularly true of two issues, namely the favored sound characteristics of certain bronze instruments including tuning models and the idiomatically acceptable width of variation, or improvisation, within some parts in the ensemble. As a proof of concept, a preliminary study has already been carried out at the University of Music and Performing Arts Graz resulting in a prototype for a computer-based system, called Virtual Gamelan Graz (VGG), which can generate the musical parts of one piece from the classical repertoire in real-time using authentic sounds. Its output should now be be expanded to other traditional pieces whose rendition will then be evaluated by Javanese musicians. The aim is to put the artists in the central position of the process of establishing to what extent musical parts may vary within the idiomatically determined limits and how general models of scales are constructed. The main source will be the mainly practical, or procedural, knowledge of the musicians which can be accessed by evaluating the musicians` response to carefully presented sounding examples of music generated by the VGG system, instead of abstract verbal discourse which is not well suited for clarifying indigenous concepts of musical aesthetics. Musicians will also be encouraged to render alternative or idiomatically better versions on the spot by playing on real instruments. The results may be documented in written and audio-visual form and can, thus, be made available for future research and artistic projects. The method of having musical experts from a non-Western culture explain the principles behind their tradition non-verbally by responding to musical examples which do not sound alien or artificial from an intra- cultural point of view and are, at the same time, precisely controllable by the researcher will open up new paths for gaining insights into emic concepts. The Javanese artists and their practical expertise will be in the center of the project which may eventually lead to a discourse on artistic principles guiding the tradition of Javanese gamelan music both among the artists themselves and between them and other experts (scholars, composers). The project is, thus, innovative and increases international networking. It will also involve interdisciplinary collaboration both between artists and scholars as well as between humanities, social sciences and natural sciences (music computing and sound design). Since the results of the project will be made publicly accessible (Open Access), they will give young artists and composers as well as early stage researchers an excellent opportunity to obtain new qualifications and try new ideas in the context of future transcultural interdisciplinary projects.

The project aimed at investigating ways of unveiling tacit knowledge on musical concepts and current performance practice of classical Central Javanese gamelan music with the help of computer-assisted listening experiments. The two main areas to be studied were first, the way in which a given composition is actually transformed into a live performance; second, the evaluation of the specific tuning of individual gamelan sets. In the course of the project known musical rules and performance principles of Central Javanese gamelan music were applied to digitally emulate an ensemble of gamelan musicians. The sound of gamelan instruments was based on samples of original musical instruments from Java as well as on measurements of the tunings of various well-known gamelan sets. Since there is no standard pitch and interval sizes may also differ considerably in this tradition, published measurements of 12 traditional and four experimental gamelans were chosen resulting in some 1360 digital samples of sound generators which had to be calculated and manually retuned in the software we used. Audio examples of 18 traditional compositions taken from both Javanese tuning systems and their respective modes were presented to three renowned senior musicians who are also instructors at the Academy of Arts (ISI) in Surakarta, namely Bp. Suraji, Bp. Suyoto, and Bp. Prasadiyanto. Their comments on both aspects, i.e., the rendition of the pieces and the sound of the various virtual gamelans with respect to their tuning, were highly instructive. By adopting an analysis-by-synthesis approach, which incorporated only explicit and mainly generic principles of performance practice while largely omitting tacit assumptions or specific knowledge pertaining to individual pieces, it could be demonstrated that accomplished gamelan musicians have a more holistic view of this art so that correct notes are equally important as or sometimes even less so than other factors such as idiomatically adequate timing, phrasing, embellishments, articulation, and dynamics as well as contextual considerations. While most of these insights might not be surprising to gamelan experts they nevertheless underscore the necessity to approach the endeavor of letting a computer emulate a gamelan performance in a much broader way than merely refining structural paradigms on the level of a musical grammar. Regarding the assessment of various tunings listening to different ones in direct comparison proved to be conducive to an in-depth verbal discourse on matters which might otherwise remain rather vague or abstract.The project has successfully demonstrated that listening experiments with local experts in which musical parameters such as melodic gestures, timing, tuning, etc. can be controlled individually can be a useful tool in investigating musical concepts and particularly in disclosing how actual performance practices are shaped by usually implicit norms.