<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=Content-Type content="text/html; = charset=iso-8859-1"> <META content="MSHTML 5.50.4134.600" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=#ffffff> <DIV> Hammermaker’s corner 6   Ari Isaac.     I had but a vague idea of the tests I would have to pass but I knew I = had to do some deep thinking about how, exactly the tone I wanted would be = produced. The shape of the hammer press and the formers, the construction of the = felt sheets, all would depend on providing clear answers to that = question. Music, to me, is a story told in sounds (or tones). The word "story" = is a stand-in for impression, feeling, worldview and accompaniment. "story" = will do. Stories are many and varied and they sound a lot better if not told in a = monotone. To put it in other words, if they’re told with as many = shadings of volume and color as possible, or as demanded by the story being = (musically) told. Every composer of piano music, from Beethoven to Gershwin looked = for, demanded, a greater degree of lyricism, tonal color from piano makers. = Hammers designed to produce a primarily "clear" tone without the capacity to = excite varying combinations of partials across the volume range, as well as, incidentally, the current fashion to play and record music played by = "original instruments" – both fly in the face of every major = composer’s perception of musical tone. The obvious problem with producing piano tone is the one Bernard Shaw = spoke of when he pointed out that we ‘destroy our appetites in the act = of satisfying them’. The hammer blocks the string as soon as it impacts on it. = What to do about that? The common answer has been to get the hammer off the strings = as quickly as possible, to give it a minimum of contact time so less of the = tone is damped. This, to me, is a clumsy answer. It doesn’t make use of = the available energies. Regardless of how light you make the hammer, there is still a = loss of energy; the string starts to push the hammer until it falls away and we = have derived no benefit from all of that energy. It became evident to me that the hammer string contact time is a = variable. Getting the hammer away from the string as fast as possible is not the = priority. The priority, the trick, is to make greater use of the reversal of the = hammer momentum by the hammer-string impact. If the hammer were a compression = spring, the impact would compress the spring. When it began to open, when the = spring compression was released, the compressed spring would push more energy = into the string. The degree to which the spring compressed would depend on the = intensity of the impact so that the energy pushed back into the string would vary = as a function of the impact force, enabling the production, by the hammer, of = varying combinations of audible partials – tonal color. This second = transfer of energy into the string as the hammer rebounds would compensate, to a = considerable degree, for the loss sustained by the hammer damping the string. The = damped components of the tone are always; it seems to me, the fundamental and = the first few partials. The functioning of the hammer like a spring is, so I = thought and so I know now, the most efficient, most labor saving and most long = lasting way to restore most, if not all of the tonal components the impact damps = out. At this point I needed to define hardness. There are two types of = ‘hard’ relevant to piano hammers: one is the hardness which renders the felt = immobile. This inability, of the felt, to flex is caused by laquoring or by steam shrinking as practiced in Europe. The impact will, for a hammer with = this type of hardness, rob the tone of important groups of partials and throughout = the volume level the same groups of partials will be lost, damped out and = remain absent. Applying a simple test, using this kind of hard, or non flexing = hammer i.e. dividing the volume range into six steps: pianissimo, piano, = mezzoforte, forte, fortissimo and double fortissimo, the volume will increase or = decrease, depending on the direction one moves in but there will be no chage = audible in the tone color range. By ‘tone color’ I mean grouping, or = combination, of partials and fundamental frequency for a given playing intensity. It is = possible to employ various needling techniques to force the hammer to produce = some color up and down the volume range. Piano technicians have been forced to = become expert in these techniques due to the lack of hammer design by many = hammer makers. I refused to go that route. If I were going to go to the immense = trouble of making hammers – I would attempt to do it right, or = differently. The second kind of ‘hard’ for hammers, is the hardness of = a compression spring. Every compression spring requires a certain weight, pressure, = impact, before it will compress. I have, at one time, purchased a 200lb spring. = I placed a 195lb weight on top of it – the spring did not budge. When I = increased the weight to 205lbs – it began to compress. At less than 200lbs that = spring was absolutely hard, inflexible but it was still a spring. Felt, too, can be = constructed to be as springy as one wishes. In a set of hammers the = spring, like the hammer weight and size, needs to graduate so that the = ‘hardest’ spring is at the treble end graduating down to the bass. How could I get felt makers = to do what I wanted? They, like anyone else, were used to do things their own = way and, judging by what I had seen, the various hammer felt sheets showed no = sign of graduating density. In my sheets of hammer felt I wanted the density = graduation to be the result of a downward graduation in the wool fiber, all of the = sheets I’d seen appeared to be made of one wool blend with no change from = bass to treble end. Here was my next challenge and it was crucial – if I = could not get the felt I wanted… </DIV></BODY></HTML>