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Introduction
Most people, somewhere and at some time, have heard the term A-440.
They may
even know it has something to do with music. But most
people, even musicians
who should know, have little concept of what A-440 really means.
The explanation is actually very simple. A-440 is
the standard which has been designated for the note "A" above middle C.
In other words, that string (or reed, or electronic pulse, or whatever
else depending on the instrument) should vibrate at exactly 440
vibrations per second (or 440 Hz). And this standard has been accepted,
with few exceptions, world-wide.
The Importance Of "A=440" in Piano
Tuning:
But why all the hubub about a sound wave too fast to count, anyway?
After all, a piano could be tuned considerably above or below A=440,
provided the notes are all in correct proportion to each other. And the
percentage of people, even musicians, who have that mystical gift of
"perfect pitch," and thus could even tell if "A" is really "440," is
very, very small. So what's the big deal? Glad you asked. Here are a
number of answers that most good musicians would endorse:
First, the
instrument was designed to be tuned at standard pitch. The
back braces, cast iron plate, soundboard, and bridges assume that each
string will be kept tuned to its proper tension--somewhere between 150
and 200 pounds each. It is true that many older pianos were designed to
be
tuned lower, such as at A-435. But even A-435 is so close to A=440 as
to be almost imperceptible. Tuners routinely find "A" on neglected
pianos at around 417 vibrations per second--which is the correct
frequency for A-flat.
Second, the
musical establishment has accepted
A-440 as its standard. Thus, all the music heard on radio, TV,
and
recordings, as well as the set pitch of all fixed-pitch instruments
such as electronic keyboards, is at A-440. So if you can't beat 'em,
join 'em.
Third, whenever
any serious piano instruction or
study is taking place, standard pitch is extremely important for proper
ear training. This is especially important with children, whose
natural
musical gifts may be far beyond what the child can actually perform.
Thus, the child could have a gift of perfect pitch which hasn't yet
become evident, and so may become thoroughly confused and distracted by
a piano which is tuned below pitch. Let's face it, a piano tuned to a
pitch other than A-440 is simply not in tune!
Fourth,
neglecting to keep piano tuning at A-440
is risky for your piano. It could result in serious problems,
especially if and when
the owner tries to get the piano back in tune. These problems include
broken strings (even one or two can be expensive to replace); cracks in
the soundboard, bridges, or even metal plate because of changes in
string tension; and the high cost of the multiple tunings often
necessary to get the piano back in tune.
Finally, piano
tuning at standard pitch is
important because it keeps the piano tuned at some unchanging standard.
A piano simply tuned to itself (i.e., leaving "A" at 435, 430, or
wherever the tuner finds it) will continually drop in pitch just
because of changes in weather and other factors, until eventually,
serious problems could result.
The Job Of Pitch Raising
Let's assume that your piano, for some reason, is considerably below
standard pitch when your tuner arrives. We'll assume it's due to
someone else's neglect, of course. Exactly what has happened within
your piano?
Realize first that an in-tune piano is a dynamic arrangement of over
200 vibrating
strings, each one having been tuned to its proper pitch by being
tightened to nearly 200 lbs. (Imagine a 200 pound man hanging from each
string!) Let's
see now . . . approximately 200 strings X 200 pounds each is 40,000 pounds, or 20
tons!
To hold all of this tension, the piano's structure has been reinforced
with four
or five large wooden back braces (visible from the back of the piano),
a heavy
cast iron plate (weighing 200-500 pounds), and threaded metal tuning
pins pounded
into a dense hardwood pinblock (see illustration below).
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Backbraces in an upright piano
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Plate in a baby grand piano
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Tuning pins
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Now here's the problem: in the process of slipping out of tune below
pitch, your
strings have loosened to considerably less than 200 pounds. For purposes of making the point, let's
suppose they
have all slipped to 180 pounds each. Multiply that "measly" 20 pounds
by 200 strings, and you find a total drop in tension of 4,000 pounds,
or over
two tons less. Now, this could have caused a major problem or two
already, such
as a cracked soundboard, caused by the fact that the board, which
becomes compressed
by the pressure of the strings, is vulnerable to splitting at the grain
when
the pressure decreases due to a lack of regular tunings. But consider
yourself
lucky: let's suppose your piano has suffered no damage yet.
This may be difficult to picture, but try to
imagine your piano as a large archer's bow, with the strings acting as
the bowstring. Now imagine pulling on the bowstring and stretching it:
what happens to the bow? Though it offers some resistence, it bows
inward, which in turn makes the string somewhat looser than it would
have been if you had pulled it out with the bow being totally firm.
The piano, like the bow, is somewhat flexible
also, despite all the strength built into its back structure to support
its 20 tons of string tension. Thus, when the tuner begins to tune
those below-pitch strings, each string he tunes causes the back
structure to "give in" slightly. By the time he has tuned all 200-or-so
strings, the piano has "bent" considerably, and thus is out of tune by
the time he finishes the job. Even though a good tuner will allow for
this drop in pitch by tuning each string higher than its correct pitch,
it is impossible to do this with precision because each piano reacts to
the pitch raising differently.
Upright Piano, cutaway view, before and
during pitch-raising
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Before:
As the strings loosen up
over time,
the back structure
settles in to
the lower string
tension, and
is resting
comfortably
there.
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After:
The increased tension from
tightening
the strings causes the
back
structure to give in slightly,
thus loosing
the strings which have
already been
tuned.
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The bottom
line, then, is that a piano that is
considerably below pitch must be tuned more than once if it is to be
put properly back in tune!
One question that often arises is whether or not a
given neglected piano can even be brought back to standard pitch. Most
technicians will tell you that a majority of them can. The exceptions
are the following:
- Pianos with
old, tired strings that break when
pulled up to pitch. These pianos are the exception rather than
the
rule. But if replacing all of the strings is not a reasonable option
(this can be an expensive job), such pianos are best left below pitch
to live out the remainder of their lives with dignity.
- Pianos with
excessively loose tuning pins.
Some degree of looseness can still withstand the added tension of
standard pitch, but at some point the pins must either be treated with
a pin-tightening solution, or, if the tuner feels that will not be
effective, left below pitch.
- Pianos with
obvious structural damage. These
cases, which include such conditions as a cracked pinblock or plate, or
split back braces, are very unusual and in most cases signify that the
piano is Dead At Any Pitch (D.A.A.P.).
The conclusion of the whole matter? Remember that
all of the above problems, for the most part, apply only to the
neglected piano. With regular tunings and maintenance (at least once a
year, and preferrably twice), your piano should remain near standard
pitch and live a happy life.
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