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"Currently, Crescendo does not provide a direct “disable MIDI input” toggle or a way to fully disconnect a MIDI device from within the software interface. The MIDI input remains active for notation as long as the device is connected and selected, regardless of sound output settings.
Workarounds:
Physically disconnect the MIDI keyboard from your computer (unplug the USB or MIDI cable). Crescendo will stop receiving MIDI events once the device is disconnected.
If you want to keep the keyboard connected for other uses, you can try selecting “Computer Keyboard” as the MIDI input device in the MIDI Input Settings. This will redirect input away from your external keyboard, so only the computer keyboard (or onscreen keyboard) will input notes.
If you want to temporarily stop input without unplugging, you may need to close Crescendo or disable the device at the system level (e.g., Device Manager in Windows), but this is less convenient and not specific to Crescendo.
Summary:
Crescendo does not currently allow you to fully disable MIDI input from a connected device via software settings; the only reliable method is to disconnect the MIDI keyboard or switch the input device to something else (like the computer keyboard)"