The PTG technical bulletin on humidity control discusses this topic in further detail. A piano also periodically requires a service called voicing . Because the tone changes as the felt hammers wear, periodic voicing of the hammers is necessary so that your piano will have an even, full tone throughout the entire scale, and produce the widest possible dynamic range. The PTG technical bulletin on voicing discusses this subject in further detail. The three components of musical performance that need to be adjusted periodically are pitch, tone, and touch.
Tone is maintained by voicing , and touch by servicing the piano action, called regulation . .
Regular maintenance also can prevent expensive repair in the future. Most manufacturers recommend servicing at least two to four times a year to keep the piano sounding good and working properly each time you sit down to play. This is especially important the first year of your piano's life. Some tuning instability should be anticipated during the first year because of the elasticity of the piano wire, combined with the piano's normal adjustment to the humidity changes in your home. A piano which has gone a long time without tuning may require extra work in pitch raising .