Can't get midi keyboard to add notes
I have an old Yamaha P 120 88-key electronic keyboard. I've tried plugging in the midi in and midi out cables and then USB cable to the computer. I connect everything and then turn the computer on, the keyboard on and then start Musescore. When I press "Note input mode" - nothing happens when I press a key on the Yamaha. I can input through the computer keyboard or the mouse, but nothing happens from the Yamaha keyboard. I can't figure out what is wrong!?