(801)
255-TUNE Click to Schedule Appointment
|
WHY DOES
A PIANO GO OUT OF TUNE?
The
following short
statement was prepared by William Braid White, Mus. D. for his book,
Piano
Tuning and Allied Arts, a number of years ago. It was later adopted by
Steinway and Sons, of New York, at Steinway Hall, and for the use of
Steinway
dealers. It is reproduced with the permission of Steinway &
Sons,
and
because the facts presented are likely to be very useful to
professional
tuners, who so often have to make clear to owners of pianos the ins and
outs of a question easily understood by technical men, but very
mysterious
to the laity.
In
order to
understand why
a piano goes out of tune, it is first necessary to remember that the
whole
instrument is always under a varying stress. The two-hundred-and-thirty
odd strings are stretched at average tensions of from one hundred and
fifty
to two hundred pounds apiece; so that the iron plate, together with the
heavy wooden framing carries a strain totaling from eighteen to twenty
tons.
Now,
this
stress is not
constant, for the reason that the steel wire is highly elastic. The
soundboard
is merely a thin sheet of spruce wood averaging three-eighths of an
inch
in thickness. If it be properly constructed, the whole board becomes
something
like a highly elastic spring. The more elastic it is, the freer and
more
agreeable will be the tone emanating from the piano.
SENSITIVENESS
TO ATMOSPHERIC
CHANGES
Unfortunately
this very
construction is extremely sensitive to all changes of temperature and
barometric
pressure. Thus, in summer time, through out the greater of the country
there is much moisture in the air most of the time, and rain is
frequent.
Wood, under these conditions, swells up, nor will any kind of coating
protect
a wooden soundboard from these influences. On the contrary, when the
heat
is on during the colder months, the air in the rooms becomes much
drier,
owing to the evaporation of moisture, and failure to keep on hand open
vessels of water, flowering plants or other moisture retainers or
humidifiers.
Consequently
the moisture
in the soundboard rapidly passes off, the board shrinks, the strings
slacken
down, and the pitch drops.
CONTINUAL
VARIATIONS
Now
it is
perfectly evident
that even where conditions are not extreme, and even in climates which
have only a comparatively short range, this process is continually
going
on.
Every
change
of a degree
in temperature, or of one-tenth of an inch in a barometer, has its
effect.
The soundboard of the piano, then, is always slowly rising and falling
through short distances, and constantly, therefore, suffering
variations
in its ability to hold the strings up to proper pitch.
On the
other
hand, if the
piano be neglected, and unless it be tuned at least once every change
in
season, say four times a year, during Spring, Summer Autumn and Winter,
it will not stand in tune.
THE
TRUTH
ABOUT STANDING
IN TUNE
From
the
layman’s standpoint,
four tunings a year should be sufficient. The tuner knows however, that
if he had time to tune his own piano as often as his ears tell him, he
would tune it once a month at least.
From a
strictly scientific
point of view, it is probably true to say that no piano ever made has
stood
in tune, without a drop or a rise for more than twenty-four hours,
unless
it were maintained at constant temperature, and under constant
barometric
and hygroscopic conditions in a laboratory.
THE
NEGLECTED PIANO
So
much
then for the frequency
and need of tuning. If a piano is neglected, if it be allowed to go
through
from one season to another, say, from Spring to Winter, without tuning,
it will probably at the end of that time be considerably lower in pitch
that it was originally. It will have gone through a rise, followed by a
fall, and the fall will be greater than the first rise.
No
matter
what any salesman
may say, no matter how finely the piano may be made, no matter, in
fact,
what the physical circumstances or the price, or the domestic
conditions
may be, there is no such thing as a piano standing month after month in
tune. The better the piano, the more frequent and careful tuning it
should
have.
A fine
piano
is a work of
art. Therefore, to treat it roughly, carelessly or negligently is to
commit
a crime against a beautiful piece of expensive craftsmanship. To pay a
lot of money for a fine piano and then allow it to go to ruin for lack
of expert care is not merely aesthetically wrong-it is bad business.
HUMIDITY
CONTROL
Your
piano
is made primarily
of wood, a versatile and beautiful material ideal for piano
construction.
However, being made of wood, your piano is greatly affected by
humidity.
Seasonal and even daily changes in humidity cause wood parts to swell
and
shrink, affecting tuning stability and touch. Extreme swings in
humidity
can eventually cause wood to crack and glue joints to fail.
Other
materials in your
piano also are affected by changes in moisture content in the air. The
many felt and leather parts in your piano’s action can change
dimension,
affecting regulation and friction, or stiffness of the touch. Very high
humidity can even create condensation on metal parts such as strings,
tuning
pins and hardware, eventually causing them to rust.
How
does
humidity level
affect my piano’s tuning?
Swelling
and
shrinking of
the piano’s soundboard is the most immediate and noticeable effect of
humidity
change. The soundboard, a sheet of wood approximately 3/8 of an inch
thick,
is made with a slightly crowned shape. The strings pass over the
soundboard
and are connected to it by a wooden piece called a bridge. The upward
crown
of the soundboard presses the bridge tightly against the strings.
As the
moisture level in
the soundboard increases during periods of high relative humidity, the
crown expands and pushes the bridge harder against the strings. The
strings
are stretched tighter and the piano’s pitch rises. Because this
increase
in crown is greater in the center of the soundboard than at the edges,
the pitch rises more in the middle octaves than in the bass or treble
registers.
During
periods of low relative
humidity the soundboard shrinks, reducing the crown and decreasing
pressure
against the strings. The pitch drops, again with the greatest effect
noticeable
in the center of the keyboard. When relative humidity returns to its
previous
level, the average pitch of all the strings will return to normal,
although
the exact pitch of individual strings will be slightly changed from
their
original settings. Thus, a piano only will stay in tune as the
soundboard
remains constant. Extreme humidity changes require making greater
changes
in string tension to bring the piano into tune. This upsets the
equilibrium
between the string tension and the piano frame, and the piano never
becomes
stable.
What is
relative humidity?
Wood
swells and shrinks
in response to changes in the relative humidity of the air around it.
Relative
humidity (RH) is the amount of moisture contained in the air, compared
to the maximum amount of moisture that it is capable of holding. The
moisture
content of air is affected by weather as well as conditions and
activities
within the home, while the moisture-holding capacity of air varies with
temperature. One way of thinking about RH is that it is a measure of
air’s
tendency to absorb or release moisture to its surroundings. Thus when
the
RH of air in a room increases, moisture will tend to transfer from the
air to wood and other absorbent materials in the room. When the RH of
air
decreases, moisture will transfer from other materials back into the
air.
The RH of the atmosphere is always changing by the hour and, more
dramatically,
with the seasons. Consequently, the wood and felt parts in your piano
are
constantly changing dimension as they absorb and release moisture.
Since
RH
depends upon the
temperature and moisture content of the air, it is not possible to
maintain
a constant RH by controlling room temperature alone. In fact,
maintaining
an even temperature while moisture content varies will cause RH to
change.
What
can be
done to minimize
humidity problems?
Keeping
the
humidity level
around your piano as constant as possible will help it stay in tune
longer
as well as slow such damage as soundboard cracks, loose tuning pins,
and
glue joint failures. The first and simplest precaution you can take is
to position your piano away from areas where it would be exposed to
extremes
of temperature and humidity such as heating and cooling vents, stoves,
doors and windows. Direct sunlight is especially damaging. If your home
is not well insulated, an interior wall is preferable to an outside
wall.
Controlling
the humidity
within the home is another step you can take to preserve your
instrument.
In most areas of the country the relative humidity is very low during
the
cold winter season, and very high during the spring and summer. In
other
areas these humidity cycles are reversed. Wherever you live, you have
probably
noticed the symptoms of low RH (shocks from static electricity when
sliding
out of a car or after walking across carpet), and the signs of high RH
(limp, soggy-feeling newspapers and sticking doors). To monitor RH
changes
in your home, you may wish to purchase a moderately priced wall
hygrometer
available from most instrument supply companies or electronics stores.
Use of
a
room humidifier
during dry seasons will help somewhat. However, too much moisture added
to a room during winter months can cause condensation to form on cold
surfaces
such as windows, eventually causing mildew, rot, and, in extreme cases,
damage to the building structure. During the humid season
de-humidification
is needed. If your humid season is winter, keeping the home evenly
heated
will help. However, humid summer situations require much more elaborate
de-humidification systems. Unfortunately, it is seldom possible to
adequately
control the relative humidity of a piano by controlling the room
environment
alone.
A very
practical and effective
answer to humidity problems is to have a humidity control system
installed
in the piano itself. These systems consist of three parts: a humidifier
for adding moisture to the air, a dehumidifier for eliminating excess
moisture,
and a humidistat or control unit which senses the RH of the air within
the piano and activates the system to add or remove moisture as needed.
These systems are designed to maintain the RH of the air within the
piano
at the ideal level of 42%. The components are installed out of sight,
inside
the case of a vertical piano or under the soundboard of a grand. They
are
easy to maintain, and can be installed by your piano technician.
How
will
humidity control
benefit my piano?
While
not
eliminating
the need for regular piano maintenance, humidity control will allow
more
stable tunings by reducing the radical pitch changes your piano may
experience
through the seasons. When your piano stays closer to its correct pitch
level of A-440 (A=440 cycles per second), your technician does not have
to perform a large pitch raising or lowering procedure prior to fine
tuning.
Thus, a balance of forces is maintained between the strings and the
frame
of the piano, allowing more accurate and stable tunings to be done.
In
addition,
a stable environment
will help to preserve your piano through the years. Wood parts, glue
joints,
metal parts and your piano’s finish will all last longer if not
subjected
to excessive humidity swings. Maintaining the correct environment will
preserve your piano investment for a lifetime of enjoyment.
PITCH
RAISING
Your
Piano, just like
every piano, is designed to sound its best when tuned to A-440 (the A
above
middle C vibrates at 440 cycles per second), the international pitch
standard.
It has been designed to perform at a specific tension, and when strings
stretch beyond, or drop below this tension, pitch adjustments are
required
to bring it back to A-440. It’s important to remember that maintaining
your piano at standard pitch allows you to play along with other
instruments
which are all designed to this same standard. Through neglect, pianos
may
deviate from this standard, making them unsuitable to play with other
instruments
and causing them to lose market value. In addition, lower pitched
instruments
can compromise the pianist’s ear training.
It’s
important to note that
pianos do not go flat or sharp uniformly. Some strings will invariably
change more than others.
If I
haven’t
had my piano
tuned regularly, how can I get it back in good playing condition?
After
years
of regular use,
your piano may have fallen silent when the family member who studied
music
moved away from home. Though your home is no longer filled with music,
it’s important to remember your piano is still a living, breathing
thing.
Its wood continues to expand and contract with seasonal changes in
temperature
and humidity, and the string tension also fluctuates accordingly. If
your
piano has gone without tuning for an extended period, its pitch may
have
dropped far below the pitch at which it was designed to perform. It may
require procedure technicians call a "pitch raise."
Why has
my
piano become
out of tune?
Changes
take place because
your piano’s overall pitch is dependent upon changes in the relative
humidity.
In some temperate regions of the country, the relative humidity
increases
in the summer resulting in a higher moisture content in the soundboard
and a higher string tension (pitch). In the winter, when heating
systems
dry the air, the soundboard loses moisture and contracts, causing the
pitch
to drop. The drop in the winter tends to exceed the rise in the summer,
so the net result is a drop in pitch each year that the piano isn’t
serviced.
In some parts of the country where the cold season is exceptionally
long,
the annual drop can be considerable. In other parts, mild winters
combined
with dry summers cause the cycle to be reversed. You can, however,
greatly
increase the stability of your piano’s pitch by maintaining a
relatively
consistent humidity level in the room.
Why is
a
pitch raise necessary?
When
the
tension of each
string on a piano is raised back up to pitch, the additional load on
the
piano’s structure causes the pitch of previously adjusted strings to
change.
The only way to achieve a fine, accurate tuning on a piano is to have
the
tension of all the strings so close to their proper place that altering
the tension of one string would not affect the others. Therefore, a
piano
must already be fairly close to standard pitch in order to be finely
tuned.
Wouldn’t
it
be easier to
just tune the piano to the lower pitch?
Tuning
to
anything other
than the international standard of A-440 is seldom appropriate. If a
very
old piano has been allowed to remain appreciably below pitch for a long
time, some strings may break if the piano is restored to A-440. Your
technician
will advise you as to whether repeated tunings will correct the
problem,
or if the piano should be completely restrung or rebuilt.
If a
piano
has dropped in
pitch, the drop will not be even. The middle (tenor) section of the
piano
usually drops most along with the high treble section. The bass section
tends to drop least. Consequently, a piano that is tuned to a pitch
that
is below the international pitch standard would have to have
significant
adjustments made to the tension of every string, resulting in an
unstable
tuning. It’s much more reliable to bring the piano up to standard pitch
and then to proceed with fine tuning.
How far
from
the standard
pitch must a piano be before a pitch raise is necessary?
Pianos
that
have been subjected
to severe changes in humidity routinely need pitch raises before a fine
-tuning can be achieved. For example, if A-440 has drifted only two
cycles
per second to A-438, a separate pitch raise is advisable. Most
recreational
musicians would want to have their pianos tuned before the pitch drops
that far. Even if you aren’t bothered by a slightly out-of-tune piano,
it’s best to tune the piano on a regular basis to avoid tuning
instability
and the extra cost of a pitch raising procedure.
Like
your
car, your piano
is a major investment which deserves to be protected by regular
servicing,
which can head off preventable problems in the future. But most
importantly,
your piano will sound its best and give you and your family the most
pleasure
when it is tuned regularly and kept in proper playing condition.
|
Piano Tuning | Regulation
| Repair
Servicing
Communities
along the Wasatch Front
|