I create my tracks in BIAB then export to Logic Pro to add vocals and mix. I also have the TCH Harmony Singer for harmonies. If I understand it right, it will control the chord change harmonies with midi, but not with the exported WAV file? I have routed the WAV output of the rhythm guitar into my TCH with poor to no results and have wondered if it was even possible to control the chord changes without actually playing the guitar with it at the same time. It will read and respond to a midi channel? Is keyboard or rhythm guitar part the best for best results?