Hi again. I have had a quick look at the code, but seeing what uses MIDIIO32 is rather tricky. For your other questions

Code is written using VB5 (except for the 3rd party stuff like MIDIIO32, which is C++)

The black boxes at the top are no doubt the dynamic icons. The content of these is modified at run time, which may be a problem for LINUX. But they do not provide anything which is not also on the menus. I will try to get a screen dump to you of what it should look like.

The problem of having read-only files has also occurred on some versions of Windows. I have never found out why, because it has never happened on my systems. It may be that the OS does not release the file properly after it has been written.

I do not know how to set file permissions within VB - maybe someone could help me there (I suppose it is just modifying the attributes using the file system code)

The music fonts (truetype)are included with the distribution. I will look up what they are.

Harmony plays midi files by calls to Windows Multi Media interface. But is there a LINUX version of MIDI Mapper? you may have to assign your MIDI out device to get sound.