Cristofori's innovative genius notwithstanding, the confusion in understanding his actions goes way way back. There are two distinct Cristofori actions: the first, shown in the Mafei drawing, and for which there is no extant version, and the later ones, as in the extant pianos and a lone aciton that is somewhere on the left of the Rockies. The hammer heads on the 1720 met mus. Cristofori are not original (in fact most of that piano is not original). Open core hammer heads are very effective. Cristofori's, by the way, are rolled paper, not parchment. Open hammer heads were used by Andreas Stein in his early pianos, and continued by David Schiedmayer until the end of the 18th century (he used cane which has a natural taper and cut it into strips like salami). There are some distinct advantages to be gained from this approach. Someone (not possible to decipher the multiple layers of quoting) wrote: >Still, several similar features do not make true the claim that >"Cristofori developed the piano action as we know it today" which is >what I was responding to. The piano action as we know it today is >designed to play a massive instrument and provide rapid repetition >while slinging tremendous amounts of weight with one's fingers >(hopefully, without injury). Cristofori's design was meant to play - >well, a "Gravicembalo" - a five octave harpsichord, essentially. He >did not have to deal with all those issues of weight, the instrument >was not expected to fill more than a largish drawing room or >perhaps dining room with its sound, Mechanical comparison doesn't necessarily maintain scale. We might consider whether a much lighter action such as cristofori is mechanically equivalent (or close to) a modern action regardless of dimensions are so on. However.... > and so I scratch my head at why he got into all that complexity >with intermediate levers that I see in his 1726 vintage action. This is actually the clue to why cristofori's design in NOT the same as a modern action. The problem comes from trying to classify actions, for which Pfeiffer must take some of the blame. "Pushing" action may well describe on some level both cristofori and the hopper action, but mechanically they are totally different. >The much simpler - but quite effective - "English" hopper-type >(that's "jack" in todays terms) action and the much more agile >"Viennese" action served pianodom quite well for close to 100 years >(yielding the music of Hayden, Mozart, Beethoven, among others) >before the double escapement came on the scene, and the Erard design >owes much more to the English hopper-action than the Cristofori >design. Yes. The true heir to cristofori is actually Stein's mechanism, which he arrived at via the intermediary of Silberman, who essentially copied cristofori. All of Cristofori, Silberman, Stein, and the later Viennese actions (Walter and so on) rely on geometry to disconnect the escapement mechanism. These types of actions have intersecting arcs that eventually fail to intersect due to their relative motion. On the contrary, the English hopper action, and later Erard types actions, disconnect by mechanical means - e.g. an inclined plane which evenutally forces the escapement. Cristofori needed the intermediate lever to reverse the arc of the key so as to achieve the disconnection, since the centres of the hammer and key arcs were on the same side. Stein took Cristofori and inverted all the components, putting what was on the ground (e.g. heammer rail) on the key and vice versa. He also inverted the direction of the hammer, which eliminated the need for an intermediate lever. In effect the key itself serves the role of the intermediate lever. [Much of the above analysis, by the way, can be attributed to Bill Jurgenson back in 1989.] I have some very interesting high speed videos of a holle hammerhead checkless Stein action which I will show in my class at Rochester. Stein never used checks because they weren't necessary with his design, as can be seen in the videos. In fact, a properly regulated checkless Stein action cannot be made to double strike no matter how hard you hit the key. Most of the checkless so-called Stein actions used in modern repro fortepianos are not correct in multiple respects, and they very often bounce. Stein's action does not. No check needed. Stephen -- Dr Stephen Birkett Piano Design Lab Department of Systems Design Engineering University of Waterloo, Waterloo ON Canada N2L 3G1 tel: 519-888-4567 Ext. 3792 Lab room E3-3160 Ext. 7115 mailto: sbirkett[at]real.uwaterloo.ca http://real.uwaterloo.ca/~sbirkett
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