A Piano needs periodic action regulation to maintain the proper "feel" when a note or group of notes are played. They should all feel the same. This is achieved through a series of adjustments to the keys and action--the intermediary between the pianist's fingers and the piano's strings.
Over time the action dimensions change due to wear of the action components and keys. This is when your piano needs either a partial or full action regulation, if not a replacement of some of the components. Advanced players may require a touch weight analysis and a plan for their specific tonal and touch requirements.
An action that is badly out of regulation puts greater stress on the pianist and stresses the keys and action components, even causing strings to break. A broken string or key that doesn't play may signify some greater problem such as a poorly regulated piano.
The cost for an action regulation varies depending on the severity of wear, the need for repair or replacement, and the labor involved.
When the action, keys, and strings are very worn either partial or full restoration is required to bring the piano back to its original form. Read the next section on Piano Restoration.
Paul Dewalt, RPT
(850) 339-2415 Tallahassee, the "Panhandle," and S. Georgia
Modern pianos are tuned to A440 hertz using the Equal Temperament. The intervals are "widened" or "narrowed" so they are "equally" in tune regardless of the key signature.
A piano needs regular tuning to maintain proper string tension. The tension on one string is 160-plus pounds, and there are 200-plus strings.
Seasonal variations in temperature/humidity is one reason a piano goes out of tune. The wood expands and contracts, thus the strings go sharp or flat. All stringed instruments have this problem.
Some pianos need piano climate control systems where wide variations in temperature/humidity occur. Ideally it is best to keep your piano in a stable environment, but where this is impossible a Piano Life Saver System can be installed inside or under (grand pianos) your piano. Only an experienced piano technician should install these systems. Installed improperly they may damage your piano.
The average home piano should be tuned once or twice annually. Pianos played heavily may need three or more tunings per year. Tuning only deals with the strings, and pianos experience wear over time from play and need action regulation or more. See Piano Action Regulation and Repair.
New pianos may require more frequent tunings until the strings are 'stretched out' and settled on the bridges.
Piano restoration, or reconditioning, is, as implied, the effort to "restore" the piano to original form. Rebuilding is often used interchangeably with restoration, though any technicians make a distinction between the two. In general, the difference is a matter of degree--and cost.
Restoration involves replacement of strings, action parts, repairs to the original bridges and soundboard and cabinet, the rejuvenation or refinishing of the cabinet, soundboard, and bridges. Rebuilding is more extensive: Replacement of the soundboard and bridges and pinblock.
Of course there are degrees of restoration. An apt analogy is the engine and body of a car. If you only care about how your piano plays then you may only care to replace part or all of the "engine." On the other hand you may just want a pretty piano-shaped object that looks nice and plays "okay." In that case refinishing your piano may be adequate.
A good place to start understanding how to buy and care for a new or used piano is "The Piano Book" by Larry Fine. This can be found at your local library or purchased online. Piano Buyer is the annual supplement. It includes information on acoustic and digital pianos.