Peter T

You have revealed part of the arcanery of the Stradella Bass System that is not widely available. I have elsewhere skimmed over the fact that early manufacturers used to include the 5th, but after a certain date - and I don't have all the facts as to when this occurred - there was an international agreement that all new accordions Bass Systems would omit the 5th from the chord buttons.

As to the construction of "extra" chords from the combination of existing Stradella Bass System buttons, I haven't stumbled across any writings on this. Most "Learn the Accordion" System Books don't even cover Bellows shake, especially in the early parts (doubtless why there are so many "Omm-Pah-Pah" style players out there!) let alone such advanced Musical Theory Arcanery as this.

If you were "Classical Music Method Trained" - which would be often happening on a seperate path from the "Practical Lessons" by your teacher - which is why it doesn't appear in these books I mentioned! - you would be learning Musical Theory as a seperate set of lessons with written homework, and written Exams. Judging by my personal experience, you probably wouldn't get near this sort of stuff until after 4 or 5 levels of theory exams. Either that, or you would have been expected to UNDERSTAND the theory you had learned enough to just make this sort of stuff up on your own... :-)

Good work guys!

(Music Theory? - We don't wan't no stinkin' THEORY! Be Practical Man!)

Robin