This question is one I get most often. The answer easy answer is- at least once a year. There’s more to this than it appears, however. There are factors that will affect the tuning that might make it necessary to tune it more often.
First, if you intend to use the piano for performances, such as a concert on a stage, the piano will need tuning much more often. Often, pianos on a stage are tuned several times before the performance, and during the intermission also.
Second, if the piano is moved, or subjected to changes in temperature or humidity, the piano may go out of tune. That’s why one should wait until the piano has acclimated to a new position if it has been moved. The piano sits in it’s own microclimate, and over time it will become stable in that climate. Even moving it across the room may possibly cause it to change.
Third, if you have a particularly discriminate ear, or have perfect pitch, you may be irritated if it drifts out of tune even slightly. If it bothers you, maybe you need to tune it more often.
If your piano seems like it needs tuning more often, a humidity control system, called a “Damppchaser” may be helpful. It works by adding a gentle heat inside or under the piano so that it isn’t affected so much by atmospheric changes.
The bottom line is, it depends… How good is your ear, and how fat is your wallet? And what are you using the piano for? If you can answer these questions, you can make your own decision.
