Music is the ultimate goal of the piano, an objective that sometimes gets lost among the tunings, regulations, voicings, etc., etc., etc. At the same time, we must be concerned with the quality and stability of our work and of that of the instruments. Tone, touch and tune are our daily bread, as they are for the musicians, if in somewhat differing manners.
Of great importance to
all is cost, beauty and durability, but the final stone in my echelon of priorities
is essentially ours and that of the manufacturers or rebuilders: serviceability.
In the designing and fabrication of pianos, and during rebuilding, certain practices,
procedures and oversights creep in that can have a dramatic effect on one
aspect of serviceability - tuneability. The next time you tune a piano that is pleasure
to tune, you can be assured that many factors contributed to that quality. Here
are listed few of the possible sources of trouble on those pianos that are not
as tuneable.
The tuning pins must be
round, with a consistent diameter and radius. Poor pins can be too long, too
short, out of round, change dimension from pin to pin and from the top to the
bottom of the thread. They can be poorly plated, the threads poorly cut, the
metal too soft, the holes out of place and too small for the larger gauges, and
finally, they may have unsquare tips. The tuning pin may appear to be a very
simple piece of metal, but when carefully considered, its complexity emerges to
demand our attention.
Tuning pins that are
too tight require much effort that could best be used to control the pitch of the strings. These pins leave one with less
than the best feel for the block and what the pin is doing in the block. Tuning
pins that are too loose lack ease of control, long term durability and
stability of the tuning. Pin block materials and construction need not be
discussed here except to define our requirements; rigidity, dimensional
stability, resilience and durability. If made and installed with care, all else
is fulfilled. What is required at the interface of the tuning pin and the pin
block is a slightly different matter. Wood and metal should come together with out
any other matter at all; no resins, oils, moisture or carbonized wood. Some
tall orders, but the factors of greatest importance are the care in drilling
the holes and the cleanliness of the pin and the stringer.
I have seen beckets (the part of the string
that goes through the tuning pin) so long that they have been wound part way
around the tuning pin in the opposite direction by an adjacent pin. This is a
little long; the proper length is through the pin but not out the other side. The
reasons for this are that overly long beckets make repinning that block
difficult in the extreme because the becket will not come out of the pin
without destroying the coil. The overly long becket represents a painful hazard
to the fingers when moving the tuning hammer and, finally, it looks tacky.
Coils that are not
tight against each other leave a pin too high, tend to cause tuning
instabilities and lack the beauty of neatness. On the finer gauges, a becket
can be pulled out of the hole over a period of time. This is why old piano
makers put four and five coils in the treble; also, the holes in the pins were
bigger than the holes in present pins. Three coils are sufficient; two and a
half are not.
Tuning pins that have
been left too high present several problems to the tuner, not the least of
which is tuning instability. These pins will not twist any less than lowered pins,
but the twist can be better perceived and controlled when the majority occurs
in the block instead of above it. The principle of an equal force applied to a
long and a short object will bend the longer the most applies all too well to
tuning hammer and tuning pin. Coils should be 1/16” to 1/8” above the plate. If
they have to be left higher than that because they are too tight, then they are
just that - too tight.
High pins will become looser with time because
the block/pin interface is smaller per square inch by how much too high it is.
If a 3/0 x 2 1/2” pin is 1/8” too high, it loses 0.12in2 of block/pin
interface, or 8.3% of all area. This presents substantial loss of pin security.
When this pin does become loose in two or ten years, it will then have to be
driven. Because the block has become bottlenecked at the bottom, the pins will
therefore be held firmly ONLY at the bottom, and a drastic twist problem then
occurs. This pin would not become loose beyond control for many more years if
it were down where it belongs. Besides, a loose low pin is more tunable longer
than a looser high pin. Because of the leverage, a high pin has, the upper
laminations of the block or the plate bushings can become deformed into oval holes,
which do not hold pins well.
The point is that if
they are down where they belong when the instrument is strung, there is far
less a future problem for the tuner and for the stability of the tuning, which,
after all, is the name of the game.
The strings themselves
can help or hinder the tuner. With the new and inexpensive scaling information available,
there is no real excuse for current production or for rebuilts to be untunable
because of poor scaling. I see a time not too far in the future when all rebuilts
will be resealed f o r smoothness of tuning, tone and power. There are some
that are doing this now, but soon all will be doing so in order to stay
abreast. I personally think it is wonderful that I am in a field that is
progressing and is not, as some of my customers comment, a dying industry. It
certainly is not, and we will soon be seeing more fine pianos coming into the market.
Some pianos were very
well scaled but have been repaired or restrung with the wrong size of wire.
This is not as uncommon as one might think. Never assume that because the
stringing appears to be from the factory that the factory stringer used the
right wire sizes. Or that several replacement strings are of the right size. Either
learn to use the math and calculators and rescale it yourself, or have it done
by someone who can - just to be on the safe side.
The worst thing that is
happening to piano tone, scales, and inharmonicity is strings wound with too
little copper. According to the most recent information on scaling, the copper
should come to within 3/8’’ to 1/2” of the terminus of the string at BOTH ends.
Inharmonicity increases by the CUBE of the distance left unwound. Changing the
specification of the windings from 1/2” to 1” at both termini increases the
inharmonicity by eight times. What this does to the tone is unconscionable, and
what it does to the tunability of that string can well be imagined.
Strings that are not
properly seated on the bridge can cause the pitch to shift while the note is sounding.
The unanswered question is which pitch is the proper one, the first or the second?
I have chosen the second, since it is the tone with duration. Unseated strings
also cause voicing problems.
One problem that also
has the bridge as source is one that has been notched so that the vertical plane
and the horizontal plane of the string vibration are of different lengths. The
string has an almost circular motion so the horizontal bridge notch and the
vertical bridge pin must have the same terminus plane perpendicular to the
string’s length. Otherwise, the string has severe partial mismatches and/or
false beats to the extent that unisons are difficult or impossible to tune.
When there are severe
angles at agraffes or cape bars or at the pressure bars, then the tuning pins
must be turned a large amount before the pitch changes. This can also happen
with very old strings that have conformed to the angles and those that have a
severe corrosion problem. Pressure bars can be raised (with the tension lowered
to prevent shearing a screw), the piano may need restringing, and some thought
can be given to modifying the plate slightly to reduce the angles, again cautiously.
Duplex scales can be so
out of tune that they create a lot of noise that is difficult to tune against.
I am not one who thinks that the piano will sound better without the duplex. I
take some masking tape and mute the strings between the bridge and the
aliquots, which makes tuning much easier; I then remove the tape for final
checking. If one or two notes are causing severe problems, a little plain Vaseline,
judiciously applied near the aliquot, will mute the nonspeaking length. The
Vaseline can be removed easily if need be.
Hammers that are too
hard, too soft or poorly shaped cause their own problems, as do hammers that
have too little felt.
This does not pretend
to be a complete listing of all the trouble I have seen, but I wished to show where
attention to details can make or break a good piano. Trifles make for
perfection, but perfection is no trifle.
