Why does my piano need regular tuning? How often should it be tuned? Piano technicians like me hear these questions every day.
Tuning and tightening the piano strings to bring the pitch up to a vibrating frequency of A440 is the most frequent and important type of piano maintenance, but it’s often the least understood.
For standard pitch A440, the A string(s) above middle C should be stretched tight enough to vibrate 440 times per second, also known as 440 Hz. Tuning is the task of readjusting the pitch (string tension) of each of the 230 strings so that they will correctly harmonize with one another. A440 is the standard around the world so that everyone can be in tune together.
There are approximately 230 strings in every piano, each string is individually stretched (or tightened or pulled) to an average of between 150 to 200 pounds of pressure, depending on its gauge of length and thickness, against a cast iron plate. Together with the heavy wooden framing the total strain of all the strings collectively exerts a pull of between 18 to 20 tons!
The primary reason for annual piano tuning is to keep the combined string tension up to A440 and equalized against the soundboard/bridges and cast iron plate. Sounding “good” to our ears is a secondary reason for tuning; a by-product of having the string tension “up” to where it is designed to be.
All manufacturers recommend tuning a piano 3 or 4 times the first year out of the factory as newly strung strings stretch and wood parts settle within the first few years of a piano’s life. Usually one or two tunings each year after that will keep the collective string tension “up” maintaining the piano’s structural integrity having all of the parts inside the piano remaining correctly aligned.
Aside from the initial settling, seasonal change is the primary reason pianos go out of tune. To understand why, you must realize that the piano’s main acoustical structure, the soundboard, is made of wood (typically 3/8 inch thick Sitka spruce).
As humidity goes up, a soundboard swells, increasing its crowned shape and stretching the piano’s strings to a higher pitch. During dry times, the soundboard flattens out, lowering tension on the strings and causing the pitch to drop (or go flat). Unfortunately, the strings don’t change pitch equally. As the soundboard and bridges expand and contract with the weather changes every piano is constantly going out of tune!
For this correct “string tension” reason, pianos should be tuned at least once a year even if no one is playing the piano. In this way, the parts of the piano remain correctly aligned preserving not only the beautiful tone but the value of the instrument.
Trying to save money by putting off needed tunings merely postpones a nominal expense until it grows into a much larger expense the longer the time period between tunings the flatter the string tension falls increasing the risk of string breakage during tuning as the strings will require more dramatic increases in torque to pull them “up” to standard pitch. A piano is, after all, not just a fine piece of furniture it is also a musical machine.
About this Angie's List Expert: A registered Piano Technicians Guild technician, Piano Tuner Extraordinaire owner Patsi Franklin has served the piano players, retailers and educators of Central Florida area since 1976. A certified Dampp-Chaser Field Expert and an alumnus of Yamaha and Steinway piano technician training programs, Franklin holds an music education degree from Miami University (Oxford, Ohio).
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