Hi Sarah, Have you seen any of the high speed photography of hammers striking the string? It's a real "eye opener". I do know that someone on the list has digitized them. I'd *love* to have a copy. Think about zero friction as you would a skater on ice. If there were zero friction the person would not be able to move at all. Some friction is necessary for good response. What is still at question is "how much" and "where" it should be. I still love the idea of using magnets to allow quick and simple adjustments to the "touch" of an instrument. It would make for an "upright" on steroids. Too bad that even though Hans Velo did not ask a fee for creative work that so few pianos are incorporating it. I know too that the gentleman in London Ontario is doing work in digital high speed photography of piano actions. It should be very interesting to see the results some day. At 11:52 AM 26/08/2004 -0400, you wrote: >Hi Ric, > >Just friendly discussion here, my friend... :-) > >Isn't playing with friction a bit like driving a car with the emergency >brake on? To me, it makes the car feel awkward, and I don't feel I get more >control. I feel I have less of it. I have to press the gas pedal harder to >go, and when I reach I reach this point, the car quickly lurches forward. I >quickly notice how weird the car feels when it happens, and I'm quick to say >"oops!" and release the brake. > >Experienced cooks know that sharp knives are safer than dull ones. Why? >More control. The sharp knife slides through food with less effort (lower >friction, if you will), and so energy is less likely to end up misdirected >into one's finger. > >In fact friction slightly compresses the effective dynamic range available >to the pianist. It takes more pressure to deliver a soft note, while the >highest pressure available to the pianist is still the same. Of course >friction can be compensated with leading in the keys, but only to an extent. >Less range in available pressures means less control. This would be >comparable to a wide letoff gap, which doesn't help control a bit. > >Besides that, friction is an ugly beast in that it is not consistent with >key velocity. When key velocity is zero, friction is at its highest. This >friction level is called "static" friction. When the key moves, friction >levels dramatically decrease. This is called "sliding" friction. Having >(by necessity) a friction level that changes with movement is not a bonus to >the controllability of a piano action. It's also what happens in the >emergency brake example (see above). > >Perhaps the most extreme example of the consequences of changing friction >are found in any auto repair shop, although they aren't so much a simple >consequence "static" vs. "sliding" friction -- but same idea. When a >mechanic strives to turn a nut with a wrench, he is prone to slip when the >nut breaks free. Just look at his knuckles! That's not control. > >Let's bring this closer to the piano. <grin> Put a Steinway D on its side >on a skid. Put the skid in the middle of a parking lot. Now get several >strong men to slide it around, to position it in some *exact* location you >specify. Now put the piano on a dolly, and repeat the experiment. In what >situation do the men have more control? This is nothing more than a >question of friction. In the first situation, the men are prone to >overshooting a position, due to the difference between static and sliding >friction. When this differential is reduced (with a piano dolly), >positioning is easier and (more to the point) more accurate. > >Finally, the control scenario that you paint with regard to a piano action >incorporates active sensorimotor feedback. That is: Push the key, see >whether it has traveled far enough, fast enough, correct the velocity >accordingly, see if the correction is adequate, etc., etc., until the hammer >reaches the string. Pianists don't play that way, except when the music is >very slow and pp. There's simply not enough time to do it that way. >Instead, they fire off finger movements and listen to what the piano gives >back. Then they adjust the overall output of their motor program to >compensate for anything that is not right. This is a process that is done >over several notes, not within a single note. > >These two different ways of carrying out movements involve very different >neural machinery. The precisely controlled movement of a single key is >mostly done through feedback loops involving the basal ganglia, which seem >to coordinate the whole mess. The complex motor programs that can be >adjusted as needed are a function of the cerebellum. To use your example, >when someone throws a fast ball at you, you use a motor program in your >cerebellum to hit it with the bat. If the ball is slow enough, then, maybe >then, you'll have enough time to fine-tune your swing through active >sensorimotor feedback involving your basal ganglia. Very different neural >machinery. Does the sensorimotor feedback scenario give you better control? >You bet. But you can't use it on a fast ball. It's just not that good. >Neither can you use it on 99.9% of the passages played on a piano. > >Peace, >Sarah > > > > > >----- Original Message ----- >From: "Richard Brekne" <Richard.Brekne@grieg.uib.no> >To: "Pianotech" <pianotech@ptg.org> >Sent: Thursday, August 26, 2004 5:06 AM >Subject: Re: Pinning on new flanges > > >> Ryan Sowers wrote: >> >> > I just can't understand why lower friction and greater upweight would >> > decrease the control over the dynamics? If the piano is well-voiced >> > you will have plenty of control over the dynamics. >> >> Because things are happening faster. You use less time to accomplish >> the same mechanical work (hammer to string contact efficiency asside, as >> its a seperate issue) >> >> You put 40 grams of force from the finger into the string... and you get >> more raw velocity out of an action with less friction then another with >> more. Lets use your draconian example... 20 swings on the one hand vs 3 >> on the other. >> >> It should be clear that for any given output velocity/force...etc... you >> will have to put in more effort in the latter then the former. The flip >> side of that is that you have less time in the former to do whatever you >> are attempting to do. The window between max output and min has been >> made smaller. On the one hand your fingers are required to be a bit >> stronger... on the other they are required to be able to exert greater >> sensitivty to control the increased response. >> >> Its kinda like hitting a baseball.... a slow pitch is easy to get your >> bat on... but a fast ball... On the other hand.... once you get your bat >> on the ball it will generally fly farther..... which direction it flys >> is another matter entirely. >> >> Cheers >> RicB >> >> >> >> >> > >> > */Nichols <nicho@zianet.com>/* wrote: >> > >> > The super low friction touch is going to get liked because the >> > upweight >> > feels so much more like the practice digital in the dorm that >> > they've been >> > listening to through headphones.( So what if the dynamic range is >> > about the >> > same.) Those keys really "pop"! >> > >> > >> > >> > Ryan Sowers, RPT Puget Sound Chapter >> > Pianova Piano Service >> > Olympia, WA >> > >> > ------------------------------------------------------------------------ >> > Do you Yahoo!? >> > Win 1 of 4,000 free domain names from Yahoo! Enter now >> > ><http://us.rd.yahoo.com/evt=26640/*http://promotions.yahoo.com/goldrush>. >> >> >> _______________________________________________ >> pianotech list info: https://www.moypiano.com/resources/#archives > > >_______________________________________________ >pianotech list info: https://www.moypiano.com/resources/#archives > > Regards, Don Rose, B.Mus., A.M.U.S., A.MUS., R.P.T. mailto:pianotuna@accesscomm.ca http://us.geocities.com/drpt1948/ 3004 Grant Rd. REGINA, SK S4S 5G7 306-352-3620 or 1-888-29t-uner
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