Piano tuning is the act of making minute adjustments to the tensions of the strings of a piano to properly align the intervals between their tones so that the instrument is in tune. The meaning of the term in tune in the context of piano tuning is not simply a particular fixed set of pitches. Fine piano tuning requires an assessment of the interaction between notes, which is different for every piano, thus in practice requiring slightly different pitches from any theoretical standard. We recommend that a piano be tuned at least twice each year. However, it may be necessary to have ones piano tuned four times a year, at the change of each season if climate conditions are not ideal or that one simply retains sensitive ears.
Pianos are primarily created from wood, and are affected by climatic changes. Changes in humidity result in the swelling and contracting of this wood, resulting in constant increases and decreases of string tension, thereby continually changing the “tuning.” Proper string tension and tuning must be consistently maintained.
People receive and maintain the best tone quality from their piano when it is tuned on a consistent basis. When a number of years pass between tunings, the pitch will often drop, far enough at times that two or more tunings will be necessary to restore the pitch to the proper level of Concert A-440/A-442 pitch