ABSTRACT

The experimental design was intended to discover the effect of the drone. However, the process seems to have uncovered additional evidence for a perceptual basis for the Circle of That. The work of Castellano, Bharucha & Krumhansl (1984) suggested that correlations of hierarchical ratings of tones from ten rag phrases, falling into eight of the Thats, could be represented by a somewhat circular MDS space.5 The common tone

space presented above in Figure 4 explains that circular relationship. However, the effect of the PA-SA drone is found to disturb that arrangement.