[Harp-L] Sweet Georgia Brown Question

[robert mcgraw <harpbob@xxxxxxxxxxx>]

I play this tune on chromatic, in Ab [the original key?]...the other day i was fooling around with it on diatonic , trying to figure out how i'd play it on diatonic, and found that the melody lays out pretty well [still in Ab] on a Bb harp, as though i were playing it in 2nd position.
 
My question: since what I'm doing is playing a tune in Ab on a Bb harp, technically I'm not in 2nd position, right? so what position is this? Or since the tune starts out with lots of F7 and Bb7, am i sort of in 2nd position? Could the tune be said to be in F when it begins? i know jazz tunes tend to move around in terms of their tonal centers...anyway, obviously i still have a lot to learn about harmony :-)
WVa Bob
P.S. please understand that I'm not asking what position to play the tune in, Ok?  
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