I have a question following to the topic already discussed on the "Yamaha P45 Digital Piano - Can it be made MIDI compatible?" I am soon going to get one of this digital pianos like the Yamaha or maybe a Casio and they all have MIDI at least via a USB port. Now, say I want to connect the piano to the PC to play Vst instruments, does the piano itself goes in mute automatically isolating its own generated sound or I have to turn the volume of the piano off? As I already have been using a MIDI keyboard controller I know the concept in a nutshell but as these pianos dont have a DAW button like on some modern synthesizers, I am just wondering whether PC tells Piano via MIDI to mute the sounds when connected to the Vst or if you have to turn pianos volume down or if maybe I am missing something more basic?
No, making a MIDI connection will not automatically mute the internal sounds, in the way that attaching headphones often mutes internal speakers.
You will have to do the onerous job of turning volume down yourself!
(Maybe you were worried that turning volume down would affect the MIDI output? It won't.)
Often, it is possible to disconnect the keyboard from the internal synthesizer.
If a device implements this, this function is called "Local Control Off" or "Local Off" (and then this can also be done with a standardized message sent from the computer).