Maintaining Your Piano

Pianos here in the northeast are affected by changing
climatic conditions that cause them to go out of tune with
the changing seasons. In the dry seasons (Fall and Winter)
they will tend go flat, and in the wet seasons (Spring and
Summer) they will tend to go sharp. This is primarily due to
the shrinking and swelling of the soundboard as the
moisture content of the wood varies with the changing
humidity conditions. Here are a few things you can do to
help:

Locate your piano away from any heat sources and out of
direct sunlight.
Don't put your piano in a basement - even "Finished"
basements are often relatively damp places that should be
avoided.
Run room humidifiers in the heating season, and if
conditions warrant it, air conditioners and/or de-humidifiers
in the wet months.
Try to keep the room where the piano is located a little
cooler in the heating season. This will tend to increase the
relative humidity.
Keeping plants in the room with (but never on) the piano
will help keep the relative humidity up in the Winter,
because plants release moisture into the atmosphere.
Install a Dampp-Chaser humidity control system in your
piano.

There are approximately 230 strings on a most pianos,
and each is stretched to a tension of between 100 and
300 pounds or more. So the overall tension on the
structure of the piano can easily be 35,000 to 40,000
pounds. Although pianos are constructed to be able to
withstand these high stresses, their structures are not
absolutely rigid and changing the overall tension by any
significant amount will affect the pitch of the strings.
Therefore, if a piano is very far from standard pitch, it may
be necessary for the tuner to make multiple passes
through the tuning to achieve accurate results. This is
known as pitch-raising, and can usually be accomplished
in one visit.

A piano's action is made up of a set of components that
allow the player to manipulate how the hammer hits the
string and the resultant tone and dynamic level, or
loudness. There are a series of adjustments made to the
action when it is first assembled at the factory that allow
the pianist the greatest possible control over the sound of
the piano. With normal usage, these parts periodically
need to be re-adjusted or regulated to return the action to
factory specifications and give the player the most
accurate control possible over the sound of the
instrument. Since these adjustments typically deteriorate
with use, the more you use you piano the more often it will
need to be regulated. A home piano that receives only
occasional use may go years without the need of a
thorough regulation, whereas a profession concert piano
might have it's regulation "tweaked" for every
performance. An analogy might be the family minivan that
goes in to the dealer every 15,000 or 30,000 miles for a
tune-up as opposed to the Formula One racecar that has
it's engine completely rebuilt between races. Here is a
Checklist for determining if your (grand) piano is in good
regulation.

Voicing is the process of manipulating the felt hammers to
produce a tonal quality that is even across the range of the
keyboard and at the same time capable of the widest
possible dynamic range, or loudness. It usually starts with
reshaping the hammer felts to remove string grooves in
the surface of the felt and to achieve the proper shape and
a smooth surface by removing layers of felt with a
sandpaper file. The hammers are then aligned and mated
to the strings so that each hammer hits all 1, 2, or 3 of its
strings of its unison precisely at the same moment. Then,
the density of the hammer felt is individually adjusted to
produce the ideal qualities of attack, tone, and sustain.
This last step may involve pricking the felt with needles,
carefully ironing the felt with or without small amounts of
steam, or treating the felt with chemicals to either increase
or decrease its density. Because hammer felt compacts
with normal usage, it typically produces a brighter, less
pleasing tone after a while. And since hammer wear is
uneven across the keyboard with the midrange getting
more use than the low bass or high treble, the tone of the
piano will become uneven as well. The amount of use your
piano receives, as well as the level of tonal quality you
expect from it, will determine the frequency that voicing is
required. Concert or recording studio pianos often receive
some voicing work before each use.

Here is what some major piano manufacturers
recommend regarding tuning frequency:

Astin-Weight - minimum of three first year, twice per year
thereafter
Baldwin - several times first year, at least twice per year
after
Kawai - at least three first year, a minimum of two per year
thereafter
Kimball - four tunings per year
Alfred Knight - four the first year & a minimum of three
annually thereafter
Sohmer & Co - at least four tunings first year & a
minimum of three annually
thereafter whether the piano is used a great deal or not
Steinway - at least three or four times per year or more
Wurlitzer - first year four times, at least twice per year
thereafter
Yamaha - minimum of four times first year, at least twice
a year thereafter
Young Chang - four tuning first year, a minimum of two
per year thereafter