Benjamin Carey, Alana Blackburn, Evan Dorrian, Joshua Hyde and Antoine Läng
_derivations
Integrated Records

Encounters between computers and improvising musicians can be overwhelmingly one-way. The instrumentalist begins playing. Their sound is recorded, transformed and spewed back into the space. A secondary level of input, in the form of buttons or foot pedals, allow the performer to trigger pre-programmed transformations. To minimise the disturbance of controlling the system, a second performer may operate the signal processor. How can an improvisational logic be programmed into the computer itself? How can a signal processing system not just play back to, but play with an instrumentalist? These are some questions that Benjamin Carey asked when he started working on the _derivations system in 2010.

The _derivations system analyses a musical performance in real time and creates a database of musical gestures based on that performance and, if the performer wishes, on previous performances as well. As in “traditional” electroacoustic improvisation, the program’s response is to transform and play elements of the recorded performance. Carey’s innovation is in the semi-autonomous actions the program makes in response  the live performance. _derivations tracks both the volume and spectral content of a live phrase. The statistical reduction of this phrase is then stored for comparison with later phrases and also for comparison with the phrases that _derivations itself plays. _derivations can respond through several channels or modules at once and all of these channels are listening to each other, generating results that are truly difficult to predict and so, from the performer’s point of view, semi-autonomous. Like a live performer, the modules are also conscious of when other modules are playing and so play in a broadly contrapuntal manner. _derivations can therefore “play with itself” without the performer playing at all.

What influence does the performer have in programming the system before the performance? The performer chooses a range for the lengths of phrases _derivations plays and also for their frequency of overlapping. This overlapping or density can also vary throughout a performance according to a preset trajectory.

The results, six of which have been recorded for Carey’s new album on Integrated Records, are remarkable in expanding the often linear and binary (multiply the same sort of sound as the performer or contrast starkly) of improvising laptop artists. The sessions feature drum-kit, recorder, saxophone and voice alone or in ensembles, performed by Alana Blackburn, Evan Dorrian, Joshua Hyde, Antoine Läng and Carey. They are miniature snapshots of rich sonic worlds, like intricate landscape dioramas. “Tactility” uses a library of sounds of a recorder, contrasting trills, low portamenti, flutter tonguing, melodic flurries and humming fields of sound. Without being able to see the performer and with the relatively restrained range of the digital sound transformations,  it is sometimes difficult to tell the system’s contributions from those of the performer. There is an insect-like autonomy-within-limits to the improvisations, which are constantly piquing the ears with new and only-just-unexpected sounds.

None of the recordings are longer than ten minutes and they give the impression that the program has a fairly static formal imagination. It is clear that the program treats the statistical data of each sample like a “point” or “molecule” in its system, much like the first serial composers. It would be great to hear the program extended to achieve a “molar” level of autonomous, large-scale organisation that might count the equivalent of one track of _derivations as a unit in itself.

You, too can have a play with _derivations here.

Partial Durations is a Matthew Lorenzon/RealTime project.