Well I would guess and this is just a guess. That the distance the holes are from the reed is more important for pitch then the length of the chanter itself.. If I put tape on my F for example I thereby more or less move the hole further from the reed. And this causes my F to flatten. As far as pitch goes most modern chanters are tuned to about the 480 range.. My chanter sits nicely at 479/480 ish during the winter and probally gets as high as 486! during the summer games.. But I shot for 482 to 484.