"It is quite possible some of this Melodyne/Auto-Tune type software has other uses."

Do Melodyne and AutoTune let you take an arbitrary audio recording and transform it into MIDI?

Logic's flex pitch will do this, and I also use the polyphonic audio-to-MIDI product "MIDI Guitar". But I don't correct vocal tracks or physical instruments; I create new MIDI tracks from recordings of animals and things, to be set to virtual instruments. Wondering what the best software for that kind of extracurricular activity is.