Scott,

"If I am reading this correctly OMB will only be able to play one voice in the accompaniment"

Your not reading this correctly. OMB can of course play all voices.

"I have Cakewalk Home Studio 9, I have the input ports set to MidiYokeNT:1, output ports are set to MidiYokeNT:2, OMB midi in is MidiYokeNT:1"

OMB MIDI In should be the MIDI port that you MIDI keyboard controller is connected to, not MidiYokeNT:1.

OMB MIDI Out (all channels) should be MidiYokeNT:1.

Cakewalk MIDI In should be MidiYokeNT:1.

CakeWalk should be configured so that it will send any MIDI message it receives to the Hypercanvas VST plugin (not to MidiYokeNT:2). I cant help you with that I don't use CakeWalk.

Btw did you try HyperCanvas with SaviHost? It may be easier to setup.

Jos