Jon and others,

HARMONY requires a simple melody line in order to add chords. If it find overlapping notes on any MIDI channel (i.e. polyphonic voice), then it will give a warning and omit one of the two notes.

It CAN cope with files with several tracks (voices), provided none of them contain such overlaps.

Overlapping notes can easily occur by accident when playing a tune on a keyboard. (Also,I would think that if you play an accompaniment, all notes would be sent to the same MIDI channel - is that right?)

On Cakewalk, you will probably find, if you use the piano-roll view, that one note starts before another has finished. Quantizing the track may fix the problem.

I am not sure why you got a different result on the second try. It should have done exactly the same thing. I will try loading the file when I am home at the weekend (time permitting)

In the next version, the user interface is simplified, partly as a result of introducing a multi-document interface (MDI) style, so that you can open more than one tune at a time.