Action Regulation is the adjustment of the mechanical aspects of the piano to compensate for the effects of wear, the compacting and settling of cloth, felt, and buckskin, as well as dimensional changes in wood and wool parts due to changes in humidity. Even with having your piano tuned regularly by a qualified technician, you may still, however, notice a deterioration of its performance. It’s important to note that tuning is only the adjustment of the system of strings and pins that determines the pitch of each string. Your piano also requires this periodic servicing called regulation, which attends to the mechanical parts which cause the strings to sound when keys are played.
The three systems involved in regulation are the action, trapwork, and damper system. The action is the mechanical part of the piano that transfers the motion of the fingers on the keys to the hammers that strike the strings. It is comprised of over 9,000 parts which require adjustments to critical tolerances to be able to respond to the pianist’s every command. The trapwork is the assembly of levers, dowels, and springs that connects the pedals to the action affecting sustain and dynamics. The damper system is the mechanical part of the piano that stops the vibration of the string(s) when you release the key and is controlled by the key and pedal system.
All upright and grand pianos need periodic regulation to perform their best. Frequency of regulation is dependent upon amount of use, exposure to climatic changes, and the instrument’s quality, age, and condition. If your piano displays a lack of sensitivity or a decreased dynamic range, it’s a candidate for regulation. If you notice that the keys are not level (some are higher or lower than the rest), the touch is uneven, or that the keys are sticking, the need for regulation is indicated. However, a sluggish action or deep grooves in the hammers indicate the need for reconditioning or repair.
No amount of practice can compensate for a poorly maintained action. Poor legato touch, chord playing where all notes of the chord don’t speak clearly, a gradual loss of subtlety in phrasing and an inability to execute quick passages or note repetitions evenly may be the fault of the piano – not the player.