Generally, a piano should be tuned once or twice in a year. Actually, it depends on the condition of the piano as well as on multiple other factors like: humidity fluctuation, quality requirement of sound, frequency of playing, quality of handling and of course finances.
For an amateur player it is recommend to tune once in a year. Any longer than this may cause the overall tension and pitch of the instrument to change, usually going pretty flat. Severe damage can cause a higher repairing investment too. However, if the piano is being played in a school or church, it means it is used on a regular basis. For this kind of setting, it is recommended to tune twice to four times a year.
(Do not forget to consider the overall cause of tune changing).
Generally, the more a piano is being played in public and becoming an entertainment factor on a daily basis, the higher it needs servicing. Make sure piano tuning and repairs are done from a professional technician of music.
What months are best to tune a piano?
When choosing a time of the year for piano tuning, some believe that spring and fall are the best seasons as they come after major seasonal changes. This is true, the relative humidity becomes the most ideal for a piano tuning. This means if you want your piano to perform for a longer period without major fluctuations, consider to tune in the month of April and May or October and November. The time of tuning becomes a major problem especially in areas like Northern Territory where wet and dry are the two main seasons in the entire year.
If your home or establishment has the ability to maintain normal temperature and humidity, nothing can be more suitable for a piano than that. Or you can also opt for a Damp Chaser or similar humidity control system. In general situations, the best time for piano tuning can be the months where changes in season takes place.
Whenever you decide to tune, stick with it and consider the same time every year for piano tuning. Remember, regular tuning can keep you at a constant bay of innovative music.
So enjoy yourself and make a joyful noise!