S & S capo

[fred s sturm]

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