hitmewithmuzak

I need to be able to plug in my drum pad and midi keyboard to mainstage 2. The way I have it set up now, the keyboard plays on its own, but when I play the drumpad, it plays the drum and key patches. I'm sure this is a simple thing to set up, how do I do it? Thanks edit: at the concert level, the two instruments are separated the way I need, but at the patch level, they are not.