a .kar file is simpy a MIDI file with some text tags in it.
I know all this textual tags very well since I wrote a part of the MIDI code in the Mediastation .. correction I should say that 'keyboard that's built on future promises of what it will or could be' :-)
If your sequencer is not totally braindead then a simple rename of
file.kar into file.mid
shoud suffice.
Anyway seriously speaking there are lots of KAR and MID files around and getting karaoke text displayed right (be it in a PC app or a keyboard) requires the handling of lots of cases (some files embed chords in the text tags, some use a LF character as separator, some the | char etc).
cheers,
Benno
http://www.linuxsampler.org