But to simulate the other piano strings resonating in sympathy when the sustain pedal is pressed then you want to have some chorus/echo effect at the same time as the sustain pedal is pressed.
If the piece has been recorded from live keyboard playing then removing the sustain pedal will totally change the way the piece sounds.
I don't know exactly what effect you are talking about, but with my Yamaha, the sustain pedal does cause the note to fade out once you release the key. If you don't remove the "sustain" command from the MIDI file, then the "extended decay" command will have zero effect, because there will be no note-off events to decay.
So you would either be sending the sustain command, or this (possibly fictitious) "extended decay" command, but not both.
Andrew, I'm wondering if you can clarify some of those terms for me, since I'm pretty unfamiliar with modulation. You said "You would do it by hooking a modulator to some CC input and using it to extend the volume decay phase - you can do that in the soundfont or the synth."
Let's assume that I don't particularly care how
to get this input in there (via a pedal, using the mouse to draw it, inserting it into a MIDI file with a hex editor) -- I want to see if it can be done at all and then I'll figure out a way to hook it up to my physical pedal. When you say "hooking up a modulator to some CC input", do you just mean there would be some controller change event that I can produce to make the decay longer? I have a list of CC messages here:
and I can't see anything that might do that.
Or perhaps you mean there's no built-in way to do that (in the MIDI spec), but that I could find an unused controller and edit the FluidSynth code to make it extend the decay?