It's been sometime since I've sold any GEM products, but I remember on the WK2 arranger modules you had to press a button called midi and then using the buttons underneath the display, you have to select one of the 9 different controllers you might be using. They ranger from accordion, guitar, keyboard, digital piano, etc. You must set this correctly from whatever midi controller you are using. I know in my store I selected Keyboard as the choice and I could use any midi keyboard as a controller. That
s all I had to do to make the arranger module to work. Make sure you are transmitting on the midi channel that the module is receiving on. For some reason, I sort of remember that channel 1 is the default, but I might be wrong.
Kaye's Music Scene