I have actually had people come in with a copy of music that they wrote and produced at home on some kind of music writing software, they have sang their own songs they wrote, and I did not have a problem with it.
The only thing I could see how it would be perceived as bad was that no one knew the songs, and no one knew really where it was going. But the music was not bad, the singers are actually really good. I would have to commend anyone for taking that brave of a step as to take their own music in and sing in front of a croud especially because we all as karaoke hosts know that a massive amount of songers all sing the smae things time and time again, and always the most popular music or the most over played music.
But anyone who would come to my show with their own music would only be encouraged by me, its individual, it is unique it is a true testiment to who they are, they are not singing the same songs everyone else is obviously so they deserve credit for doing so.
Two thumbs up for being individuals and most importantly not being afraid of doing it in front of a room of total strangers and possibly the worst critics out there.
And you never know that "original" song just may be popular one day and you will look back and say... yeah, I heard it for the first time at my karaoke show.
It would make me proud to have been a part of something so artisticly wonderful!