The rich rhythmic/metric construction of South Indian Carnatic music is characterized, in large part, by intricate interplay between an internalized metric cycle called the tāḷa and performed phrases that may generate expressive tension with this tāḷa.  Thus, informed listeners, who track the tāḷa using standardized hand gestures (kriyās), may experience substantial internal tension. A common source of such tension is trikāla technique, in which the performed pulse unit expands or contracts over constant tāḷa.  While trikāla has been thoroughly described performatively, historically, and culturally, it has received little attention within the music-theoretic realm. Thus, this paper seeks to approach trikāla technique from the perspective of Lewin’s (1987) transformation theory, applying the metric generalized interval system (GIS) Met developed by Wells (2015a; 2015b; 2017) to the problem of representing and quantifying this technique.

The first part of this article lays the theoretical foundation for Met-based analysis of Carnatic music, demonstrating basic techniques for representing Carnatic rhythmic/metric structures using the GIS. Of these techniques, the most significant for the current study are intervallic expansion and contraction transformations. Because these transformations are generated by expanding or contracting pulse units over a constant background meter, they are ideally suited for modeling Carnatic trikāla technique. The next two sections apply these theoretical ideas to analyses of traditional pedagogical exercises called alankārams and a rāgam-tānam-pallavi (RTP) performance previously investigated by Widdess (1977). These Met-based analyses reveal hidden aspects of the music’s metric workings, demonstrating how seemingly simple expansions and contractions of the melodic pulse unit can drastically increase rhythmic/metric complexity. Moreover, in the alankaram exercises and the RTP performance, the intervallic developments suggest a striking balance between stability and change in the relationships between melody and tāḷa. The Met intervals also act as analytical agents, representing contextual metric functions and rhythmic/metric sources of musical development. Ultimately, the analyses not only provide new insights into trikāla technique in the specific examples in question, but suggest new possibilities for rhythmic/metric analysis of tāḷa-based Carnatic music more generally.