I had trouble trying to eliminate the solo/melody/vocal parts from various MP3/WAV files -- AFTER I did the chord conversion into BIAB. Object being: keep the chords; play over that with my own melody/solo.
It's possible -- it seems -- to bring the MP3 into BIAB with the chords; then COPY the chords (but not the melody line) into a new "page". This accomplishes what I am trying to do.
Remember, I am not trying to mute parts in MIDI files, but MP3/WAV songs.
So far I have had a 70% success rate.