Filter some midi change controller message from passing thru.
Sets a midi channel on an hardware synth when the active button is true, on false, all notes note are kept playing until release.
Basically does the same as Program Change for not playing but does not send program changes because the VST Settings are all done by the DAW.
All notes On / Off are wired to a single note playing. This allows to keep arpegiator continuing until all notes are off.