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What happens at a piano tuning?

upright piano
upright piano

Who do I call to tune this thing?

Congratulations! You’re a piano owner! Maybe the piano was a “bonus” acquisition from a house you purchased or you acquired it on facebook marketplace for your children, who are starting lessons. Maybe it’s a family heirloom, passed down to you. However you acquired it, you are now responsible for its maintenance and upkeep. You might consider tackling tuning and repairs on your own. Overly positive and loquacious people on youtube assure you that you can, but a quick skim-read, of the wikipedia page on piano tuning, detailing the depth and complexity of the topic, will likely steer you toward leaving this task to the experts, which is when you call us.

grand piano
grand piano

What happens at a piano tuning?

Just like doctors in days of yore, the piano technician does make house calls and will come to your home at a prearranged day and time. They bring their own tools (quite a lot of them, as pianos can have over 12,000 parts).

Though the technician is primarily there to tune the piano, they are also qualified to work on the accessories and mechanical parts. They may check the piano bench, to ensure that it’s not wobbly or requiring any screws to be tightened. Your technician doesn’t want you to one day sit down to play and then keep going all the way to the floor.

They may check the pedals. Often pedals are improperly assembled after moves or misadjusted, especially on grands, which cause them to make unnecessary noises or feel sloppy. Technicians also adjust the pedals to ideal sensitivity. Checking for and making these adjustments does involve crawling on the floor under the piano.

After the technician has determined that the bench is not going to collapse underneath them, they will sit down and play the piano. This gives them a sense of the piano’s current state and establishes a good “before” picture. The technician will be able to determine whether the piano needs “just” a tuning or further adjustments to address mechanical issues like clicking action parts. Depending on how out of tune the piano is, these further adjustments can often be addressed at the same appointment, or they may be noted to be addressed at another time.

tuning lever
tuning lever

Will it be loud?

Tuning a piano can get a little loud, so you might want to give the technician some space for an hour or so, unless you aren’t bothered by the sound of a note played very loudly and repeatedly. Some people may find the process interesting and may wish to stay and observe. The technician will need to focus and listen carefully while tuning but will be happy to answer your questions at the conclusion.

How do they know it’s out of tune?

Technicians measure tunings in cents (or hertz). If a piano is more than 6-7¢ out of tune, the piano needs a pitch raise (officially known as an “overcorrection”). In these cases, it is most efficient to perform the tuning with the aid of an ETD (electronic tuning device). If the piano does not require an overcorrection, the technician may perform the tuning by ear. Either method requires extreme concentration and a quiet environment and are very difficult to accomplish if there are competing sounds like vacuum cleaners or dishwashers running.

tuning a grand piano
tuning a grand piano

Tuning with an ETD

Piano technicians use piano specific ETDs, which operate very differently than guitar tuners and have sophisticated settings and formulas that go into producing the tunings. (The ETD that Alaska Piano Service technicians use is an industry standard and the most advanced and heavily researched and tested ETD on the market.)

The technician starts by measuring the piano’s inharmonicity, which relates to the harmonic partials of the notes, and differs by piano model. At that point, they’ll note the stringing pattern (string scale and breaks), which also differs by model. This information gets input into the ETD.

The ETD uses its calculations to determine how far over and under each pitch needs to go. If any of the initial measurements were inaccurate, the ETD calculations will be off, so attention to detail and knowledge of piano technology is required.

The technician first tunes the unisons (one by ETD and the rest by ear). Unisons are strings that play the same note. The ETD establishes where the pitch of one string needs to be, and the technician listens to that established pitch and brings the unisons to that standard using their well-practiced ear to listen for frequency differences between the notes. These show up as a beat, and the technician uses their tuning lever to move the pins holding the strings until the beat becomes a bloom. During this process, the technician plays the notes hard to make sure the string is stable.

After completing this part of the process, the technician will play the piano again to listen for a soundcheck. Then they’ll do aural checks, which involves playing a series of intervals to test for the sound or the intervals. This also differs by piano.

Once the piano has passed these tests, the technician plays it again to make sure it sounds good musically.
If the piano was 20-25¢ sharp or flat, the tuning stability may not hold as long, and another tuning may be required in 2-3 months to stabilize the strings.

tuning upright piano
tuning upright piano

Tuning by ear

When tuning by ear the technician starts by playing A4 (A above middle C) and compares that with a tone generator. Most technicians prefer to use an app for this, as tuning forks can be unstable in pitch and affected by temperature. Tuning forks also don’t sustain as long as tone generators, and not all pianos amplify their sound well.

The technician tunes A4 until it sounds pure (no beats). Then the technician tunes F2. They’ll compare it with A4 on the tone generator and A4 on the piano and listen for the same discrepancy.

Thereafter, they set the temperament of the piano from F3 to A4 using a series of intervals, tuning each string as they go. The temperament is the distance between the different notes in an octave.

The technician uses mutes to mute the unisons so they will only hear one string at a time. After completing this section, it will become the reference for the rest of the piano.

Depending on the technician’s personal preference, they’ll work their way up to the treble or down to the bass, tuning each octave using interval checks. After tuning the octaves, they unmute the unisons in the temperament section and then tune those, as well. There are many more checks when tuning by ear, as any mistake will affect every note tuned afterward.

If tuning with an ETD relies more on math, tuning by ear relies more on instinct developed by lots of practice and experience. Every piano is different, so finding the right “stretch” (variance tuning) is an art and involves understanding what tune will be best for the piano and the preferences of the pianist.

piano technician playing grand piano

The Last Step

Finally, the technician will put everything back to make it look like he or she was never there, but your piano should sound much better.

How long will the piano stay in tune?

Depending on your specific piano, humidity in the space, and playing habits, your piano may need to be tuned every 6 months, at minimum every year, and if you’re a serious performer, before every concert. As we get to know you and your piano, we’ll help you determine the best schedule to meet your needs.


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