Still working on this. I have my midi cables now. In fact, I have two kinds. One is just one cable with a midi plug at each end. The other has two midi plugs at one end and USB plug at the other end.
I have had no luck with either one. I am probably not configuring something correctly, but I don't know what. The single midi cable has no indications marking either end as "in" or "out", so I assume they are interchangeable. The other one clearly states "plug this one into midi out" and "plug this one into midi in", so I don't think I can get them wrong. The USB end I plugged directly into the computer. Regardless of how I turn things on and off, plugin, unplug, plugin again, etc, I can't get the keyboard to show up in the list of midi inputs or outputs in Reaper's options.
So I plugged the single cable in--using midi out on the keyboard and midi in on the interface. No results. Just to cover all my bases, I reversed the plugins--midi in on the keyboard and midi out on the interface, but nothing from that, either.
There are settings for midi in Reaper's preferences but I didn't change any of them. I don't know what they mean and usually, default settings work for everything.
Any suggestions for what I missed? I read the manual for the keyboard, but it mostly just describes what midi is. There's a bit of direction on plugging in the cables, which I followed.