As humidity fluxuates, your pianos wood expands and contracts resulting in an out of tune instrument. Having your piano tuned at least once a year is recommended. In order to over come some of the effects of the our constaltly changing humidity levels, one may choose to have a Damp-Chaser climate control system installed.
Regulation is the process of aligning and adjusting the piano's action so that it will function properly. Often such maintenence is overlooked for years. Regulation should be adjusted and touch up regularly and if it has been several years, the action is likely due for a general reconditioning and regulation.
As a piano is played, it's felt covered hammers can become compressed and develop grooves. Surfacing the hammers periodically will eliminate the groves from the hammer heads. Using fine needles, the hammer heads can be properly softened in order to produce the desired tone. A very bright sounding piano may be easily adjusted to be warm and mellow sounding!
Having your piano's interior cleaned at the time of tuning is always recommended!