The opening piece at Spark, Concert 5 on Thursday, February 19, 2009 was Metamorphoses by Clifton Callendar for three cellos, or solo cello and digital delay. As it happens, it was expertly performed in the latter configuration by Evan Jones. The level and timing of the delay made the piece often sound as though there was more than one instrument present, and auto-panning on the delay trails sent the ghost instruments back and forth across the stage. The cellist was wearing headphones, perhaps listening to a click track. Here’s a short segment from the performance.
Metamorphoses by Clifton Callender
I have lots more from Spark that I would like to post, but it needs some sorting through, so here’s something of my own for now. This is an arpeggiated loop of a synthesized clavinet chord filtered in real-time with the cutoff frequency on the instrument, which happens to be the Korg MS2000. After looping it I ran it through some gentle amp modeling followed by two ping pong delays. One set very short and another set much slower. The short delay has a lot of feedback and almost sounds like reverb, while the long delay is creating the echo.
A variety of processing went into this segment of backwards Rhodes electric piano. I started with a chunk from a loop recorded during a recent performance. I reversed the chunk and then slightly time compressed in 
While working in the studio recently I plugged in a cable from an auxiliary send to record some bass and got some horrible feedback. So horrible that I was determined to record it. The reason I was getting the feedback was because the same send that I was using to record the bass happened to be turned up on the channel that I was using to monitor the signal. I realized this immediately, but the sound was quite interesting due to the subtle latency on the signal path caused by the digital hardware involved. Here’s a couple of layers of the feedback running through reverb. I also made adjustments to the pitch a time stretched the recording in a few places.