As your Wilmington DE piano tuner, I’m frequently asked why a piano needs tuning if it is seldom or never played. This post article is the third in a series of four articles explaining the importance of regular tuning of a piano. Previously, it was stated that if a piano is not tuned at least once a year, then the strings will be stressed when the pitch is raised at a later date. There are three reasons for this stress. The first reason and second reasons were discussed previously, and the third reason will be discussed in this post.
The previous two reasons were related to the gradual transfer of tension across bearing points of each string. This third reason is related to flexing of the soundboard. The soundboard is the structure of the piano which amplifies the sound emanating from the strings. Without a soundboard, a piano would be about as loud as an electric guitar without an amplifier. The soundboard is a large piece of spruce located under the strings of a grand piano, or behind the strings of a vertical piano. It is only 3/8″ thick and is glued to have a convex or “crown” shape. The reason for the shape is to put tension on the wood, so it is a live vibrating structure that amplifies sound. The strings pass over this structure and are attached to it at the bridges, which are hardwood structures at the far end of the strings. The cumulative pressure of the strings pushing down on the soundboard by way of the bridges, is about 500 lbs.
When a piano is tuned at the proper pitch, there is a stable amount of pressure pushing down on the piano soundboard at each piano string. On the other hand, if the piano has not been tuned in years, then the tension must be raised on the strings. The tension cannot be raised on all the strings at the same time. A tuner must tune one string at a time. As the tension is raised on a string, it pushes down more on the soundboard, causing the soundboard to flex. That flexion changes the tension and thereby the pitch on all the other strings in the piano. That amount of change differs on different parts of the piano, and it varies depending on the design of the piano, as well. That flexion will be further explained in our next blog post article.
If you have any questions about your piano or the care it requires, please give us a call at Kenneth Keith Piano Services, your Wilmington DE piano tuning technician. We also proudly serve the areas of Philadelphia, Southern NJ and Eastern Shore MD.