Mmmm... actually I don't know.
I just downloaded them from the net.
If,after having renamed them *.mid, I import them in Cubase,there are some lines that say:

Soft Karaoke
@KMIDI KARAOKE FILE
@V0100
@I Lyrics entered by ...
@I email: ...
@LENGL
@T Title name
@T Artist name

Is this useful? I'm afraid I can't give more information.

Regards,
Leonardo