Being kind of dopey

(I realise now!) that I sometimes have my Voicelive 2 harmonizing on midi rather than on my guitar, but actually, I only use Realtracks in my backing tracks. It seems to harmonize quite well, so I now assume that it was using the realcharts that load simultaneously because it can't use the realtracks. Is that correct? My question, how many Realtracks have these Realcharts? Can I rely on them? Sometimes I just want to sing and not strum or I'm soloing on guitar with vocals etc. I can get the Voicelive 2 to harmonize on audio, but I don't think it would be very good. I guess it would free up the midi for program changes etc.
Interesting thread, but I'm too impatient and useless for midi (1980's midi and I became acquainted!) except for playing sounds on a midi guitar, DX7s and Korgs etc. I guess I'm a Realtacks baby