I feel the same way about karaoke. Do a little bit of practice so you don't look like a fool. But, if you over-practice you'll take the fun out of having your best performance live.
I feel like karoake has a bathtub distribution. My favorites are the people who are outrageously good or outrageously bad. As long as they are outliers, it's fun. The ones in the middle who sing well enough to not embarrass themselves but not good enough to be an exciting performance are boring.
Humm, if you get everything right I would probably assume you already read about something similar which means that it is evaluating nothing or rather it is just evaluating your ability to remember things which is not that useful when you can just google it.
Pro tip for non-singers like me: Buy one of those karaoke games. Now find out the songs your voice naturally sings reasonably well. Stick to those songs forevermore.
