A piano should be tuned every six months for playability and basic maintenance purposes.
Depending on how the piano is used and its environment, it might need to be tune more frequently.
Pianos that are locations where the humidity and temperature changes often need to be tuned more often. Pianos in high-use locations like practice rooms, recording studios, and houses of worship need to be tuned more often. Concert pianos may be tuned every day! Most home pianos, however, will do well with two tunings per year.
A piano is made primarily of wood. The soundboard and bridge in particular are large and important parts of the piano made of wood. They transmit the vibrations of the strings and amplify them. As humidity changes, so do these wooden parts. Moisture in the air causes the wood to swell, which makes the strings go sharp. Dry air causes the wood to shrink, which makes the strings go flat. The changes are not uniform across the instrument, and so the piano goes out of tune.
Other environmental factors can make a piano go out of tune such as large and quick temperature shifts. Direct sunlight, heat radiators, fans, and air conditioners cause a piano to go out of tune.
Sometimes there is a physical issue with the piano, such as a loose tuning pin that will cause a string to slip. If one or two notes are significantly more out of tune than the rest, the piano might have an stability problem that is material, not environmental.
If a piano is not tuned on a regular schedule, fluctuations of humidity and temperature cause the piano to go further and further out of tune, usually flat. Bringing the piano back to pitch requires adding a lot of tension to the system. The more the change, the less stable a tuning will be.
Typically, a piano that has not been tuned for two or more years will require at least two tunings to regain stability.
Remove all items from the piano and clear a space so that the lid can be propped open. This preparation will give me more time to take of your piano during the visit.
You can also wipe down the exterior and the keys with a very, slightly damp cotton washcloth.
Please also remove young children and pets from the area. I have two young kids and two dogs, so I know the joy of a full house. However, some of the tools and materials I use are dangerous to toddlers, and I am cognizant that I am stranger coming into an animal’s safe place.
Depending on the piano and its state, I will spend two to three hours tuning your piano.
You may stay in the room, but the quieter the space is, the better quality the tuning will be. Extraneous sounds, especially loud or pitched noise, like a vacuum cleaner, make it difficult to hear the details of the string vibrations.
Of course, this is your piano and your space, and you likely have things to do, but do your best to plan a quiet activity.