I've sang Karaoke before.
The Karaoke available in the club are all really old songs; their 'new' songs were released 2 years ago or before. O__O
So you won't find Taio Cruz's 'Dynomite' there. No, you won't even find 'Fireflies' by Owl City.
The songs are available in Cantonese, Mandarin, English and many other languages... haven't been there for a while... never really sang a Japanese song there...
If they have 'Special Days'/'Gorgeous 4U'/'My Secret'/'Hoshi no Nagareru Yoru Ni' there, I would surely sing it...
But most of the english songs available are kid songs. (eg. Twinkle Twinkle Little Star, Old Macdonald had a Farm, etc.) though I've sang Disney songs like 'Beauty and the Beast' there... it's a waste to go there. (Though I would go there if I wanted to practice singing mandarin songs lol)