Thank you for your enthusiastic responses! I'll try to go into a little more detail...

Hmm... First of all, the system does not process audio at all. I only have a 750mhz P3, and I found that trying to do control & audio at the same time was too much. The timing was not stable enough, so I use a separate program to handle the audio generation / FX, and the pd side only generates MIDI / control data. Audio is disabled in pd.

Basically, my system consists of a number of "generator" patches, all of which use GOP. There is one that plays MIDI files, there is one that generates patterns of notes in a given scale (which is set globally), there is one that generates chords, etc.. Each of these generators can be turned on or off, routed to any midi channel, and have a number of other parameters.

Under the hood, it is simply generating, processing, and routing around <note,velocity,duration> vectors.

There are also a number of patches that spit out numbers: one that approximates an LFO, one that puts out random values within a given range at a given time interval, etc. etc.

There are a number of parameters that can be applied at the channel level or the global level:

• density (what percentage of notes are actually played)
• pitch (using pitch bend)
• repeat (sort of like delay, but it actually retriggers the note n times)
• velocity
• randomness (remembers the last n notes it heard and spits them back

out randomly)

• duration (can modify the duration of all notes at once)
• etc, etc...

I have these different parameters assigned to knobs on my midi controller. I also assign some knobs to pass control data through to the VST effects.

It uses a "pool" based preset switching system (thank you!), and I have the buttons on my midi controller assigned to jump between the presets.

When performing I only have a minimal amount of stuff on the screen, almost everything is hidden away because jumping between presets causes timing glitches due to all of the GOPs.

I hope that gives you a general idea...

If you're interested in hearing more, here's another live performance in which I used the pd system:

http://bill.teamtechno.com/music/william_fields_-_live_at_hologram_1-7-2004.... (download, 83MB MP3)
http://bill.teamtechno.com/music/william_fields_-_live_at_hologram_1-7-2004.... (stream)

Cheers, -Bill http://www.williamfields.com/