I can't really see any problems in allowing entry of chords and/or text at the same time as notes in Harmony.

I could arrange to put up a form which contains a text box for each, triggered by a key press, and which would apply by default to the last note input. (You already have the facility to add these later, including the title, by using the standard edit menus)

HARMONY does not use text boxes and frames within the score display, the data is actually attached to the Note object and the display is generated dynamically.

HARMONY does not yet allow graphics (e.g. Guitar chords) within the score, but I could look at this - it should be possible.