I just added a Midi Keyboard to my setup here and it works fine with Dorico. I setup a Midi track in Cubase and it recognizes it but I haven’t found a way to assign any instruments to it. The documentation is not very good on this question, so, hopefully, someone can tell me how to do it.
Doug 
I’d recommend you use Instrument Tracks instead of MIDI Tracks. They combine both the MIDI and the Instrument into a single Track type and they are generally easier to use. When using a MIDI Track you need to load the Instrument independently & then connect the MIDI Track to it. If for some reason you really want to use MIDI Tracks then read up in the manual about Rack Instruments which are what you’d connect the MIDI to.
Raino,
Thanks, that did it. I’m new to DAW so I assumed that using a Midi Instrument is all I had to select… now I know.
So much to learn…
Doug