On Jul 18, 2008, at 1:12 AM, David Ilvedson wrote: > Does anyone know if the NY Steinway Sost system or the Hamburg Sost > system came first? The patent for sostenuto dates way back to 1874 - for a square of all things, then adapted to uprights and grands in 1875. The Steinway site has what appears to be a complete listing of Steinway patents, unfortunately just titles, dates, brief description, and patent number. Searching the US Patent office http://www.uspto.gov/patft/ under patent number 164,052, I found a drawing that seems to show a bellyrail mounted system. There is another sostenuto patent in 1916, which appears to be for the hinged tab, though the picture may imply mounting to the action bracket. I had some problems with viewing some of the images (there were supposedly four pages of drawings for the 1916 one, but I was only able to view one. No text for patents that old). Maybe someone else will have better luck. In any case, it appears that what Steinway initially invented for the grand piano was belly mounted, and that at some later point they switched to the current NY action mounted system. Regards, Fred Sturm University of New Mexico fssturm at unm.edu
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