Hi Larry,
no doubt you're right, but what I was actually trying to say( in my own muddled way haahaa) was, that if you wanted to use an audio file ( derived from a midifile, or a sequenced song, or an audio loop etc) to play in sync with a kn file, your kn file would have to be recorded as a technics sequencer file (not a midifile) so that the audio file can play along in sync, ie
record your song,
then play an audiofile in sync with your song.
Purpose of the audio file is to add parts or sounds that don't exist in the kn ie add an audio drum loop, add an audio vocal track, add an audio live guitar strum etc etc

I totally agree that it's not worth saving a normal kn midifile or sequenced song as an audiofile because of the space it takes up, but when you find something special, then it's worthwhile.

I actually had a friend record some backing tracks for me to play along with. He recorded them on his Wersi as a wav file, I then converted them to an mp3 for use in the kn7 as an audio file. In short, I had his wersi playing the backing song and I played the melody using the kn7. Sort of a music minus one setup.

best wishes
Rikki