Most people that I know that use an arranger for vocals, rarely, if ever use the harmonizer...they find it too gimmicky.

I think it would be great for recording, but, I wouldn't use it live either.

I like playing without accompaniment too...keeps the piano chops up. One night, I played a whole set using an acoustic guitar sound instead of piano...of course, this was in a restaurant setting, so it was easy to do. It went over quite well.

Best wishes on your gig tonight.

Ian