Over time, the strings in a piano become stretched out and go "flat", bringing the piano out of tune. Other factors can affect this, such as weather, sunlight, humidity, how much the piano is played, how much the piano is moved, and how often the piano is tuned, all of which may alter the shape of the wood and metal components of the piano and exacerbate the effect. The more time passes by, the more this process occurs, to the point where a piano can come to sound extremely unpleasant.
For an example, watch the videos here on the left of a severely out of tune piano, and the same piano after tuning. (It normally takes more than a decade without tuning for a piano to get this bad. This piano in particular hadn't been tuned in 31 years, and its sustain pedal wasn't working properly, though I was able to fix it.)
Tuning re-streches the strings and brings the pitch back up, for a time, making it sound as it should (until the gradual de-tuning process occurs again). For a typical family piano, tuning usually need not take place more than once or twice a year. For pianos that see frequent or professional use, three, four or even more times may be necessary. For concert hall pianos, tuning is typically done before every performance.
Tuning itself does not fix other problems in the piano, such as sticky keys, an uneven keybed or grooves in the piano hammers; these are separate issues (and while I can identify them and perform some simple repairs, these problems are best fixed by a dedicated piano technician.) But tuning is the single most straightforward thing you can usually do to get your piano sounding better.
To schedule an appointment, click here, or use the contact form below: