I used Audacity to sample A3 played on my Concertina Connection Hayden Peacock and I got this frequency analysis graph:
The first peak (the fat one on the LHS) is A3, the second peak is A4 and the third peak is E5, the fourth is A5, the fifth is C#6 and so on.
I understand that these represent the overtone series and that they are what I should expect to see, what surprises me is the amplitude of the second overtone (E5). It appears to be louder (in the graph) than the played note which seems wrong?
(I started doing this because I suspect that midi players are also confused by the frequencies generated by concertina samples. I am pretty sure that midi players sometimes pick the second overtone rather than the sample tone because it has higher amplitude)