I happen to be a karaoke fan, and I have karaoke software on my (Fedora) laptop. The software is opensource, it's called Performous [0] and it's not in Fedora because it uses ffmpeg, but it's in RPMFusion. I have a couple of USB mics that work with it. I have also collected over the years a fair amount of songs to butch^W sing to. I have songs in English, French, Spanish, some German and a couple songs in other languages (like Swedish or Japanese)
Would you be interested in me organizing a karaoke session for that evening? I'll just need a videoprojector and a (small) sound system to plug into. The downside I can think of is that it's likely to make the room less suitable for silent board games.