In mid-2017, New Haven, Connecticut double bassist/composer Carl Testa began to develop a SuperCollider-based music processing system he called Sway. Testa envisioned an autonomous program that could take individual musicians’ sounds as inputs, perform signal analysis on them, and on the basis of the results obtained, respond by modifying them with a given effect. A two-volume set of four Sway-enhanced performances recorded between September, 2017 and October, 2018 documents how Testa implemented the idea over several iterations of his program.
As the tracks on both volumes demonstrate, Sway has been an organically evolving program, changing and adapting as circumstances warranted or as Testa wished. Each improvised performance featured the system at a different stage of its development–although all stages, even the earliest, show a high degree of sophistication in design and execution. For the earliest piece, Three Sections, recorded with the mixed ensemble of Erica Dicker on violin, Junko Fujiwara on cello, Louis Guarino, Jr. on trumpet, Andria Nicodemou on vibraphone, and Testa on double bass and electronics, Testa conducted the players and triggered the processing himself. On the next piece, the hour-long Quadrants for the same group with the addition of vocalist Anne Rhodes, Testa eschewed personal intervention in favor of using a pre-arranged timetable to regulate the process of effects assignments. By the time of Emergence, also for sextet, Sway had evolved to the point where, in place of a set timetable, it could control the changes in sound sculpting through a more fluid, real-time interactivity with the instruments.
What Sway does exceptionally well on the three ensemble pieces is compose with color. Whether controlled by human input, timed sequences or real-time response, Sway moves instruments in and out of the foreground and mixes their voices in varying and unpredictable combinations. The closest analogy to listening to these performances would be to watching a multicolored Calder mobile set in motion. The timbral richness of the instrumental input—high-, low- and middle-compass strings; brass; mallet percussion; and voice—and the players’ evident skill in interacting with each other and the program, are both crucial elements in these performances.
Which is why the last piece on Volume 2, Bloom, a solo improvisation for double bass recorded in Hamden, Connecticut in mid-October 2018, is so interesting for what it shows of what Sway does given the limited input of a single instrument. The sounds fed into the system are more austere and consequently serve to lay bare with a dramatic clarity the metamorphoses, distortions and enhancements Sway injects into the flow of a performance. The spare lines and episodic structure of Testa’s improvisation dovetail nicely with the pacing of the program’s shuttling between, and overlapping of, granular synthesis, pitch alteration, delay and other effects. Here one can hear quite clearly how the system works: how it creates a dialogue with itself as well as with the instrument fed into it.