I have been using vArranger for a long time with Ableton Live (host) and Soundfonts, Bandstand and Halion Sonic(accompaniment)and kontakt, Bardstown, Garritan and many others for my right hand voices. In addition, I use Antares as my vocal harmonizer.

It works very well - sounds excellent, reliable and effective. There is no noticeable latency. To make this happen you need a fairly good PC. It may even work on todays gadgets, e,g., IPads, tablets, laptops, etc.

Frank