I have a hard time believing that the "default pitch" for plucking spokes would be a middle F. Shorter spokes, like on the rear drive side, would have to be looser than the non-drive side spokes to get the same pitch. Plus, you'd get interference from the other spokes that cross the one you're plucking. Don't get me wrong -- I agree that listening to them will quickly point out which ones are under- or over-tensioned (Easton says that their wheelbuilders fine-tune with pitch) -- but I don't think that there's a so-called correct pitch.

I wouldn't mind being corrected on this one, though. I can hum you an F right now, and probably within 10-20 "cents", too.