Hi Christian
Yes you can tweak your own voice.
Lower,like Barry White or rougher like Louis Amstrong or higher like a soprano.
You can also use Vocal Harmony (VH) with this you can sing as a choir with 4 extra voices.
As an option you can buy Voice Modeling and Pitch Correction,to understand what it is listen to the demo on
www.korgpa.com I hope this anwsers your question.
Merry Christmas
Jan