Disklavier

I am unclear about the Karaoke function of the Yamaha Mk4 disklavier. 
It is advertised in all markets as having this lyric display function 
on video out or the tablet, yet there seems to not be any music made 
for it. I read that the only lyrics you will get are from the tune 1000 
format and yet that site says there will be no live acoustic from  
those. So what software is working for the mk4 that utilizes the lyrics 
display and the acoustic piano parts that Yamaha advertises. Will the 
midis with embedded lyrics that you can get on the intenet work with 
live music and show the lyrics. 

Thanks and I hope someone can offer some helpful advise on this subject.