The guys from zplane had a nice preview from there new software vielklang instant harmony v2.0.
Harmonize your vocal track with one single click and create natural-sounding background choirs instantly!
vielklang instant harmony v2.0 is the second generation of harmony generation with artificial intelligence. In contrast to traditional harmonizers vielklang not only generates mere parallel voicings but utilizes harmony progression and voice leading rules to generate a musical and natural arrangement.
It automatically recognizes the input melody’s pitch, musical key, tuning frequency and its melodic phrases and magically generates musically meaningful and natural voicings.
The critically acclaimed zplane élastique pitch shifting engine ensures pristine audio quality and detailed editing of pitch and timing.
More info on www.zplane.de.