M-Audio KeyRig 49 does not seem to be recognized by GarageBand

I recently purchased a used M-Audio Key Rig 49. I cannot seem to find a way to select it (or even find it) as an input source in GarageBand. The computer finds my M-Audio FastTrack immediately. It recognizes it and I can then select it and record with it.

When I plug it in with USB, it lights up (blue lights over the octave buttons).

Here's what I've already tried...

I have tried two USB ports and two USB plugs as well as restarting the computer.

I have gone into Applications>Utilities>AudioMIDI Setup> and then selected MIDI Devices. It shows a generic USB Midi device and when I initially tested it, it did not respond - now it does 'ping' when I hit the keys (I ran a software update and another restart).

I have gone into GarageBand>Preferences>AudioMIDI>and I've tried all of the drop-down options for Audio Inputs (Fast Track, Built in Mic, Built in Input & System Setting) and none seem to work.

Of course, I've tried all 3 track types (Software Instrument, Real Instrument & Electric Guitar.) It seems you can only select inputs for Real Instruments and Electric Guitars - but as I mentioned above, my input options don't include the keyboard.

Any help would be appreciated. Thanks.