As your piano tuner Wilmington DE, I’m often asked why a piano needs tuning if it is seldom or never played. This is a continuation of the explanation from my previous blog post. 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 will be discussed in this post, and the other two reasons in subsequent posts.
To understand the first reason, some information on the construction and design of a piano are required. Each string on a piano has three parts. A piano string is attached to a hitch pin at the far end of the piano; the second section, or “speaking length” is in the middle of the string and is the portion that we hear vibrating; and the third section goes from the speaking length to the tuning pin. The first section of string is muted off with cloth so that it will not sound. It is a few inches long and runs from the hitch pin to the piano bridge, a wooden structure attached to the piano soundboard.
At the bridge is a bearing point which separates the first section from the second section, which is the portion that is heard. This bearing point at the bridge causes a slight kink in the string, so that the sounding portion is abruptly stopped at a specific place, helping to assure clear and reproducible sound. That kink also creates resistance to changes of tension in the string.
If the tension is raised on the speaking length of the string, it takes about ten minutes for the tension to equalize across the bridge. As the tension rises on the first part, or tail of the string, the tension will decrease on the speaking length. As a result, if the tension must be raised on a piano that has not been tuned in a long time, the tension must be raised higher than the needed final tension, as it will fall over the first ten minutes as the tension equalizes over the piano bridge. This is the first reason that the string will be stressed during a pitch raise. In order to compensate for the loss of tension over the bridge to the tail of the string, the string must be pulled higher than the tension needed to be the proper pitch.
If you would like a further explanation for any of these principles, or if you are in need of an expert piano tuning Wilmington DE and/or other piano services, please give us a call at Kenneth Keith Piano Services, your piano tuner Wilmington DE. We also provide professional piano services in Philadelphia, Eastern Shore MD, Southern NJ and the surrounding areas.