As a classic instrument, the upright piano is very important for its performance, and tuning technology is the key to ensure the stability of the pitch and frequency.
First of all, the selection and use of tuning tools are the basic points. Professional tuning wrenches are indispensable, and their size and precision must be closely matched with the piano's tuning pins to ensure accurate operation when adjusting the tension of the strings. In addition, it is necessary to use tuning forks or electronic tuners to determine the standard pitch, usually based on A4 (440Hz or 442Hz). During use, the tuner needs to rely on rich experience and keen hearing to carefully turn the tuning pins with the wrench to make subtle changes in the tension of the strings and thus adjust the pitch. For example, when the pitch is low, the string tension needs to be appropriately increased, but attention should be paid to the control of the force to avoid excessive force on the tuning pins to avoid damage and affect the frequency stability.
Secondly, there are strict requirements for the order and method of tuning. Generally, the tuning starts with the reference tone A4, and then the other strings are adjusted in sequence according to the specific interval relationship. A commonly used method is the "four-fifth cycle method", which is to gradually determine the height of each note by adjusting the fourth and fifth intervals. In this process, the tuner needs to listen carefully to the harmony of the intervals and determine whether there is a beat phenomenon. Beats are periodic changes in strength caused by the slight difference in the frequency of two notes. Beats are eliminated by adjusting the tension of the strings, so that the intervals are pure and harmonious, thereby ensuring the relative stability of the frequency in the entire piano range. For example, when adjusting the fifth interval, if there is a clear beat, it is necessary to fine-tune the tension of one of the strings until the beat disappears and the interval is accurate.
In addition, the structural characteristics of the piano itself have an important influence on tuning and frequency stability. The length, thickness, material of the upright piano's strings, and the hardness of the hammers will affect the pitch and frequency changes. Over time and with the increase in frequency of use, the strings will relax due to stretching, resulting in a drop in pitch. Therefore, regular tuning is not only to calibrate the pitch, but also to compensate for this physical change in the strings and maintain frequency stability. At the same time, the hammers will wear and deform after hitting the strings for a long time, affecting the strength and timbre of the strings, and indirectly affecting the pitch. The tuner needs to take these factors into consideration when working, and properly organize and adjust the hammers to ensure the overall performance of the piano.
Finally, the consideration of environmental factors is also an important part of tuning technology. Changes in temperature and humidity can cause the wood and metal parts of the piano to expand or contract, thereby changing the tension and pitch of the strings. For example, in a humid environment, the expansion of the wood may cause the pegs to loosen and the pitch to drop; while in a dry environment, the strings may shrink and tighten, and the pitch will increase. Therefore, the tuner needs to understand the characteristics of the environment in which the piano is located, and reserve a certain adjustment margin when tuning to adapt to the impact of environmental changes on frequency stability. In addition, it is recommended that users install humidity control equipment in the room where the piano is placed to maintain a relatively stable temperature and humidity environment, reduce interference with the piano's pitch, and extend the time it takes to maintain the pitch after tuning.
