How the Piano works

    When you hit a note, up to (and sometimes more) then 130 parts go into action!  I guess that is why the mechanism of a piano is called an ACTION.  A piano action can contain over 11,000 parts.  Making all these parts work together is imperative for the piano to respond as it should.

    These thousands of parts are made of wood, felt, metal, leather and even plastic.  Each of them have dozens of adjustments which must be within thousandths of an inch.  Many of these adjustments are so small they can't be measured using tools or gauges.  They just have to be "felt".  This is called REGULATING the action

    At the back of each key, is the WIPPEN.  To me, this is what ties everything together.  The hammer assembly (with shank and butt) is connected to the wippen.  Only the butt actually contacts the wippen.

    When you hit a key on your piano, it lifts the wippen.  This causes the wippen to engage the butt and thrust the hammer toward the string (a distance of about 1 7/8 inches).  When the hammer is about halfway to the string the DAMPER lifts off the string to allow the note to sustain until the key is released.  The sustain or sostenuto pedal will hold the damper off the string after the key is released.

    The top 20 keys don't have dampers.  This is because the higher frequencies don't naturally have as much sustain as the lower ones and they are not needed in this area.  In addition it allows these strings to vibrate sympathetically with the others on the piano causing a brighter or fuller sound to the entire instrument.

    Now...  remember we left the hammer traveling halfway toward the strings.  Just before the hammer hits the string, the wippen turns loose of the hammer and the momentum of the hammer's motion (remember Newton's law?) causes it to continue to the string on it's own.  This happens about 1/8" to 1/16th of an inch from the string.  If this didn't happen, the hammer would be pushed against the string and would cause the hammer to stay against the string and muffle the tone.  This sometimes happens when a piano is badly out of regulation and is called BLOCKING.

    When the hammer rebounds off the string, it again contacts the wippen.  When the key is released, the wippen moves back under the hammer and the dampers go back to their position against the strings (stopping the tone), unless the sustain pedal is depressed.

    This is highly oversimplified but should give you an idea of all the "stuff" that has to happen when you hit just 1 key on your piano.

    Now, most pianos have 3 pedals.  The left pedal is the soft pedal.  Most of the time this operates by moving the hammers closer to the strings so the hammers strike the strings more softly.  On a grand piano this pedal is called the UNA CORDA pedal and it accomplishes the same thing by moving the entire action one way or the other so that the hammer will only hit 1 or 2 strings as opposed to all 3.

    The middle pedal operates the bass sustain on most pianos.  In some it will lower a piece of felt between the hammer and strings (called a practice mute) which greatly muffles the tone.  In some others (mostly grands) is is called a sostenuto.  This causes the dampers to lift off only the notes that are depressed when the pedal is depressed.

    The right pedal is the Sustain pedal and lifts the dampers away from the strings so the strings can continue to sound after the note is released as previously explained.