At 17:18 05/15/2003 -0400, you wrote: >Greetings, > Here is a new one on me, it comes from the piano-L list: > >Jon said how this tone was produced, I can't remember what he said >other than that he struck two notes, a fourth apart, and that in doing so, >the low G was produced. He said that organists do this to compensate when >they do not have pipes which go low enough. > >Can anyone explain this to me? << > > >Ideas, anyone? > >Ed Foote RPT Yup, they're called difference tones, or what the organists call resultants. What you are hearing is a beat speed equivalent to the fundamental. If you recall that the difference in frequency between _each_ harmonic in the series is equal to the fundamental, you can see that, to some extent, _each_ pair of adjacent harmonics will produce a fundamental resultant. The fourth (IV) just happens to have a strong enough resultant to be heard and usable. The purer the interval, the stronger the resultant, of course. Naturally, a tuning system which has purer fourths and fifths will aid in this phenomenon being observed on a piano Conrad Hoffsommer Early to rise: early to bed; Makes a man healthy, and socially dead.
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