<html> ric, et al, If it hasn't been mentioned yet, here is a good book that contains information along these lines: "The Acoustic Foundations of Music" by John Backus WW Norton Co., published 1966, revised 1977. Great book. Resultant tones have been used by organ makers and transister radio makers for a long time. Don Mannino At 12:21 AM 12/3/2002 -0800, you wrote: <blockquote type=cite class=cite cite>At 11:43 PM 12/2/2002 -0600, you wrote: <blockquote type=cite class=cite cite>> If we are presented with 400+500+600, > provided the relative phasing of these components doesn't drift, we >hear100.  This is called the "missing fundamental" effect. Who calls this the missng fundamental effect?</blockquote> I don't know, Ric, but I think I know an example. Debussy ... La Fille aux cheveux de lin (Maid with the Flaxen Hair) Bar 26, or thereabouts, has a progression of three chords. The first (bottom to top) is Ab, Eb, and Gb in the left hand, and Cb and Bb in the right. The second is Db and F in the left hand, and Ab and Db in the right. Then it resolves to Cb, Gb, Cb in the left hand, and Gb, Cb, Eb, and Gb in the right. (No doubt he got the flats on special, with a volume discount ...) The trick being, that the ear hears the top line as being Bb - Ab - Gb, while the Ab only appears an octave below, but the partials are so strong that one hears the ghost note as if it were a real note. All this is enhanced because the dynamic is piano going to pianissimo. This seems to be kind of like upper partials pinch-hitting for a fundamental, so I suppose it might be considered a "missing" fundamental? Anyway, very fun effect, and a good test for the resonance of pianos. Susan _______________________________________________ pianotech list info: <a href="https://www.moypiano.com/resources/#archives" eudora="autourl">https://www.moypiano.com/resources/#archives</a></blockquote></html>