I have a vocal harmoniser on my Korg's PA4 - It really is amazing.
I rarely sing, but I was dying to have a go. So, I chose a number by Pink Floyd called 'Breathe' which has strong vocal harmonics, and I gave it a go...it's only short you'll be pleased to know.
I managed to do the whole thing 'live' i.e. singing and playing at the same time.
No laughing, please!
Here is a link to my efforts! Click the orange marker on the Soundcloud LINK below to ‘Play’.
https://soundcloud.com/peter-s-7/korg-pa4-breathe-vocal