This paper describes the process used to create a compositional instrument for live performance. I include this as a possible case study for how another system would be integrated into a live performance engine, or how it represents a live performance engine with missing pieces that will be identified through the construction of a theory about how live performance engines should be structured.
The process they follow is one of a continual feed back loop between ideation, experimentation and rehearsal. By iterating this cycle they are able to gradually build up the technology necessary to support the performance as well as its content and physical constructs. Their process was also very collaborative with ideas and realizations coming from many artist's efforts, including from the performers themselves.
The author notes that during the integration phase of the work they had to meet together for many hours of work:
This work began in the summer of 2001 at the Columbia
University Computer Music Center, where we met on a regular basis to test
the successful integration of the violin writing with the Max/MSP system.
During our countless hours testing and rehearsing in the studio, Cerar
provided invaluable critique and ideas regarding both the violin material
itself and the types, settings, and balances of processing applied to it; and
Geers worked to adjust both to increase their effectiveness.
Also, they note that a trial and error method was necessary for development of the piece both in the physical construction of movement and the technical and auditory construction of the interaction:
For us (Geers and Cerar), the process of these rehearsals was quite interesting,
because its experimental, trial-and-error method of developing the final
presentation was quite unlike the rehearsal process in classical music. In fact,
it was much more like our experiments months earlier at the Columbia
Computer Music Center, when we spent hours upon hours adjusting details of
the violin part and audio processing—Except this time our entire bodies were
involved, performing the music, moving across stage, embodying characters, etc.
The cockpit style of the Max/MSP control patch is interesting to observe here. In this case they used DSP presets to modify the many knobs and dials and numbers that were available to control the compositional engine. Presets are a provided element within Max/MSP. They could have really benefited from a built in transitioning mechanism to smoothly fade many numbers, dials and knobs from one value to the next. In addition, a physical control surface (some sort of physical interface such as a midi knob set, keyboard, or joystick, etc) would have also provided an added improvisational capability to the system.