What is a Pitch Correction?

A pitch correction is a preliminary tuning, or pre-tuning, done before a fine tuning in order to ensure the stability of the final tuning pass. Most piano technicians would agree, that aside from the tuning itself sounding awesome, stability is the most important thing a piano tuner can impart on your piano. A great sounding tuning doesn't mean much if it can only be enjoyed for a short period of time.

A fine tuning requires that a piano be only a few cents off from the target pitch. When too much time has passed without a tuning, or there has been a significant change in a piano’s environment, particularly humidity, the result is typically (not always, but usually) a drop in pitch. As the pitch continues to drop over time, so does the amount of stress on the soundboard, bridge, plate and frame. Pianos, being the stubborn instruments that they are, need time to adjust to large changes in string tension. During the first tuning pass, already-tuned notes will not usually stay where they were left. Only when the entire piano has been brought reasonably close to the target pitch will the tuning remain stable, hence the need for a pitch correction.

So, to answer the question of whether or not your piano might need a pitch correction, it really depends on several factors: the amount of play it has received, the degree of humidity the instrument is subject to and the amount of time passed since its last tuning. A consistently tuned piano is less likely to require more than a single fine tuning pass, but regardless of the level of neglect, an experienced piano technician will quickly be able to prescribe a course of action to get your instrument back into a stable pitch.