By default, the hold pedal (foot switch) sends CC#64 Sustain. But it can be configured to send any other MIDI control change number, including CC#66 Sostenuto. When the hold pedal is configured, the display shows "SostPedalS #66" rather than just "#66". That suggests that Sostenuto is or is supposed to be implemented on the Virus. But I have not been able to get it to do anything. (CC#64 Sustain works fine.) Has anyone else got CC#66 Sostenuto working? If so, is there a trick to it?
If you are wondering what Sostenuto is supposed to do, it emulates the behaviour of a grand piano's middle pedal. With Sustain, note release is blocked for all notes played while the hold pedal is on. With Sostenuto, all notes that were already on when the hold pedal is pressed will have their releases blocked while all notes played while the hold pedal is on will release normally. A typical use would be to play a chord and, while the chord is held down, press Sostenuto, then, while Sostenuto is on, take the hands of the chord and play some more notes. This is really good for sustaining a chord without having to hold it down while playing a melodic run over the top of it.
Simon