Well the idea is to write a keyboard instrument playing program, but instead of having the notes arranged as in a piano-like keyboard (white and black keys), they should be arranged like in accordion bass:
![Image](http://www.jimlaabsmusic.com/images/uploads/accordions/excaliburBassButtonChart.jpg)
the program would be used to play the accompaniment part of a song, so it should be able to play chords (Major, minor and 7th).
An example of what I want to realized is this youtube video
Unfortunately I am not an accordion player so I don't know all the details (note values etc) but I think I can sort these details out.
The problem is the sound capability of the Vic20. For example the 7th chord requires four voice channels but Vic has only three. So instead of using plain voice channels I was thinking of implementing single-voice with arpeggiato effect (to understand, the "0" effect in amiga mods). This way it should be possible to play multiple keys pressed simultaneously. But as far as I can remember I haven't seen the arpeggiato effect used in vic20 music (I might be wrong).
So, just give me your suggestions,idea,impressions... is the whole thing doable, worth the effort?