---------- > From: Robert Scott <rscott@wwnet.net> > To: pianotech@ptg.org > Subject: Inharmonicity in other instruments > Date: Thursday, June 11, 1998 9:58 AM > > > > It might be awkward, but imagine that you could somehow get a > bow to scrape across a piano string. What would happen to the > inharmonicities that you knew were there when the string was struck? > They would vannish! The partials would be exact multiples. Now > suppose that while you were bowing the piano string you gently > lifted the bow off the string and allowed the string to ring > free. The resonances of the string would then be free to vibrate > at their own natural frequencies and the inharmonicity would come > right back! > > Robert Scott > Detroit-Windsor Chapter PTG If this is true, then shouldn't the FAC readings on a SAT be different for a bowed piano string? If one were restringing the bass, with all of the bass strings removed, the first string could be put on and should be easy to bow. It would be interesting to see the differences a SAT or other ETD would show between the partials when bowed or struck. There are also theories about the diameter of the string causing sharpness of partials, which is well illustrated in McFerrin. He shows how this causes the nodes to take up space on the speaking length, thus shortening the vibrating segments, which would make those partials sharper. If this is the case, I don't see how bowing could affect inharmonicity caused by diameter. There have been conjectures that some tones especially those from sine waves have no partials. But it is hard to imagine two sine waves an octave plus one cps apart not beating. Or two sine waves a tempered third apart not beating. Richard Moody
This PTG archive page provided courtesy of Moy Piano Service, LLC