I think it is useful to distinguish between two different effects of the S & S capo, with its relatively low angle of deflection (also present to varying extents in other pianos). First is the positive aspect, IMO, which is an additional "bloom" in the tone, and a reinforcement to the variation of partial mix with change in impact speed of the hammer. This area needs to be able to be heard over a tremendous amount of volume available in the lower areas of the piano. It is in these upper areas that the melody must be brought out. Taking off my technician cap, and speaking as a pianist, one often needs to bring out upper notes in a very thick texture, using the poor old pinkie to bang out the melody, which is especially difficult when playing chordal music with other fingers of the same hand playing simultaneously. It is necessary that a small amount of extra "pressure" of an individual finger can somehow serve to make one hammer's impact stand out among many. This is achieved in part by the gradation in elasticity of hammer felt (becoming harder, thus exciting more upper partials), and in part, in the Steinway design, by exciting "noise" in the front duplex section. Now maybe the latter results in a loss of sustain, but, once again IMO, the gain outweighs the loss usually. A side-effect of the low deflection angle is the tendency to create obnoxious sizzling noises. Usually these aren't noticeable to an audience in a recital hall, but they sure are annoying and distracting to the performer. One can get rid of them, often but not always, by surfacing the capo at that spot, knocking the offending strings sideways in either direction, lowering pitch until the string moves a bit around the hitch pin (all these with dramatic temporary loss of tuning stability), or by muting off the forward duplex section by inserting hammer felt wedges, folded bushing cloth, or the like between two strings. Doing this, of course, also results in loss of the "bloom" or whatever one wants to call the positive effect. (Of course, the noises can also be coming from the bridge termination, which is another subject). I guess I shouldn't omit that one can also voice them out by needling the hammer in some instances. My thought is that if you have a harder capo, you are less likely to get the obnoxious noises, because there is less likelihood of minute bits of metal coming loose and zinging against the string. At any rate, it makes a lot of sense to give extra attention to dressing the capo surface and removing any metal dust before stringing. Many thanks to those who responded to my query, with the PTJ citation and with practical experiences. Fred S. Sturm, RPT University of New Mexico
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