Mark,
There is no technical difficulty in doing it, but that's not compatible with the main objective of HARMONY, i.e. to add chords.

For this reason, the internal tune structure does not permit polyphonic voices.

HARMONY can import a full MIDI file to its Event List display, but this is not very useful at the moment, and the Microsoft Flexi Grid control seems VERY slow to load. About the only thing you can do with it is save it in a different format (i.e. it can convert from format 0 to 1 and vice versa)

Neil