Why Do Pianos Go Out of
Tune?
Think of the sound-producing portion of the piano as
being like a drum. There is a wooden frame with an iron support (plate) to which two hundred and thirty or so
strings are attached under tension. When
the total tension of all the strings is added together, the frame must hold
exactly in balance from eighteen to twenty tons of pressure. The ability of the
piano to have power and full tone requires the foundation of the piano to be at
a precise balance of tension and compression.
Like a drum, some parts must remain stationary while other parts are
free to vibrate. In a piano the
soundboard must be free to vibrate.
The very nature of wood gives it resonance
and strength, but also makes it very sensitive to atmospheric
fluctuations. Wood is hygroscopic,
meaning it takes in or gives off moisture from the surrounding air. When humidity is high wood swells and when
humidity is low it shrinks. This
constantly affects the balance of tension and compression in your piano.
Since piano wire and the cast iron plate
are not affected by humidity but wood is, the balance of tension and
compression is constantly changing. This causes the tuning of the piano to
fluctuate. Any person living in the Midwest knows our weather can change at the
drop of a hat. Twenty to thirty percent humidity changes in 24 hours are
common. This creates a difficult
environment in which to keep your piano in tune. The more stable the surroundings, the more
stable your piano will be. The finest
and the poorest instruments alike are all affected by humidity.
A quality piano is both a work of art and
a highly refined machine. To keep your
piano in it’s optimum mechanical condition requires regular service and a
stable environment. If your piano is in
an environment outside the range of 30% to 60% humidity you can likely expect
problems or even damage to occur.
Manufacturers are not liable for problems caused by extremes in humidity
so it is important for you to be aware of the conditions your piano encounters.
In a new piano there is a settling process
that takes place over several tunings as the piano acclimates to its
surroundings. Since new piano wire
stretches and wood responds to humidity fluctuations it takes a while for a
piano to stabilize. After your first
in-home service call, I suggest that you tune your piano again in three to four
months. After that, again in four months
and from then on we suggest a bi-annual schedule. By following this maintenance schedule you
will see many years of exceptional service from your piano. For questions
please feel free to call me: 317.439.7083