My grandfather played several instruments in a 'brass band', finally settling on the tuba. he said it allowed him to get a seat on the tram - just drop it on someones foot, and when they stood up, sit.

AF takes 3 octaves on the piano accordion - you would really need a Low G whistle, and need to cross-finger or half hole the G# as it is a dominant part of the whole piece. The C natural on which the whole second part hangs needs to be clear.

It really is in the mode of D plagal.

Robin