'medieval nine pipe portative organ'.

Almost all the ones we know about had far more pipes than that, though usually only one chromatic note (B flat), if any.

Bagpipes typically have nine available notes. The Highland pipe repertoire alone has something like 20,000 pieces. If you play an instrument like that you don't see a limitation.


Such primitive instruments were limited to specific notes and modes are a result of that kind of limitation.

Which is why modal thinking of some sort is used by almost all players of the commonest instrument in history, the diatonic harmonica. Every time you do a "position shift" or play "cross" you're using a modal concept.

Modes are very much a living idea.