I love to sing some karaoke, although I am not very good.
well maybe you should try sing-along songs instead as then you don't need the lead vocalist.
but then there is no fun in that! What do you think?
Have you heard of the Diablo Swing Orchestra? They formed in 2003.
Singing
Sorry? THe line up features instruments that you don't usually see in a metal band, like a cello. 
I have not, what type of music do they do?
Metal. Like Viking metal which is black metal with influences from Nordic folk music. Not good for karaoke!
Oh okay I understand. What kind of instruments are used then?
Kind of like heavy metal with differences in tempo and drumming style and the guitar playing style.