Re: \' over blowing \'
The overblowing for normal open pipes is the same as it is for most all woodwind and brass instruments, namely, (starting from the main note)
In this case we'll speak of a pipe playing "C"
Jumps an octave (from the main note, to it's octave ), then a fifth, then a fourth (to the second octave), then a MAJOR third (to the Tierce pitch), then another major third (to the Quinte pitch), THEN a MINOR third (To the famed Septieme), then a Major Second (playing it's third octave), then another major second (playing D), then E, F, G, A, Bb, B, then C, then C#, D, D#, E, F, F#, G, G#, A, A#, B, C........ Etc. continuing in the same fashion......
And it just keeps going up from there.....
To get a pipe to overblow requires opening up the toe hole's diameter, and making the windstream slightly thinner and more focused by closing the flue up very slightly, pushing it more towards the languid. You could leave the flue intact as is, but it would require a larger opening thus further, and it would be considerably louder as well.
Julien A. Laurent