Real Time Probing of Modulations in South Indian Classical (Carnatic) Music by Indian and Western Musicians
We used Toiviainen and Krumhansl's (2003) concurrent probe tone technique to track Indian and Western musicians' tonal hierarchy profiles through modulations in Carnatic (South Indian classical) music. Changes of mode (ragam) are particularly interesting in Carnatic music because of the large number of modes (more than 300) in its tonal system. We first had musicians generate profiles to establish a baseline for each of four ragams in isolation. Then we obtained dynamic profiles of two modulating excerpts, each of which incorporated two of the four baseline ragams. The two excerpts used the two techniques of modulation in Carnatic music: grahabedham (analogous to a Western shift from C major to A minor) and ragamalika (analogous to a shift from C major to C minor) We assessed listeners' tracking of the modulations by plotting the correlations of their response profiles with the baseline profiles. In general, the correlation to the original ragam declined and the correlation to the new ragam increased with the modulation, and then followed the reverse pattern when the original ragam returned. Westerners' responses matched those of the Indians on ragams with structures similar to Western scales, but differed when ragams were less familiar, and surprisingly, they registered the shifts more strongly than Indian musicians. These findings converged with previous research in identifying three types of cues: 1) culture specific cues schematic and veridical knowledge employed by Indians, 2) tone distribution cues duration and frequency of note occurrence employed by both Indians and Westerners, and 3) transference of schematic knowledge of Western music by Western participants.