Boy..I have to admit that my conception of this 'octave' was all wrong. For some reason, I was under the impression that the 'killer octave' lied somewhere between C6 and E7, depending on the piano. The reason for the 'extended' range is because this is the area of a piano that is the most unstable, hence the nickname. Thanks to all for making this as clear as mud for me! Rook
This PTG archive page provided courtesy of Moy Piano Service, LLC