I've been holding off until there was something significant to report. To make a long story short, Live Help was No Help and Tech Support was basically unreachable. I finally went to Goodwill and bought a Cheap Farfisa. Worked like a champ, so I guess the problem was with my Cheap Yamaha!

Thanks, y'all, for your attempts to help me out.
LFM


Band In A Box 2013
Mac Mini (late 2012) Yosemite (10.10.5)
Monitor 1680 x1050 HDMI
M-Audio Uno Midi Interface, Yamaha DX21 Keyboard