Here's what I'm trying to do:
Use Band-in-a-Box (BIAB - a MIDI composer/arranger/sequencer program) to send the MIDI stream to the CoolSoft VirtualMIDISynth (which it does now, just fine) and also to a TC Helicon VoiceLive 3 vocal harmony processor (hardware). The VirtualMIDISynth plays the MIDI notes and responds to instrument program changes. While playing, BIAB also reads the name of the chord in each bar in the chord sheet. It then sends the MIDI notes which define the chord (ex.. C major would send the notes C, E and G - sustained) to the VoiceLive 3 on an unused MIDI channel thru a USB or MIDI cable. The VoiceLive3 uses this MIDI chord info to intelligently harmonize vocals in real-time.