Analogue-sequencer

This may be old news to MIDI veterans, but it was a fun morning for me.

I ran a MIDI cable between one of the P3 outputs and my old Lexicon PCM 
70.  The PCM 70 gives you 10 MIDI patch slots per program.  You can use 
most MIDI data (except absolute note number) to modulate any of the 
parameters in the patch.

So, as a test, I set up an aux to send MIDI CC #1 values to the PCM 70 
and routed those to modulate the delay tap levels.  This way, I could 
introduce delay on any step, for as many steps as I wanted.  Worked 
very nicely.

Expand that to multiple MIDI events and then start doing some random 
masking of those events and you can get some very cool stuff happening.

Lexicon and Eventide (among others) seem to provide fairly extensive 
MIDI control over their effects parameters.  Take a look through your 
effects manuals and have a go at it.