Physics and piano tuning
A while ago some scientists at the Universität Würzburg had this amazing idea that tuning a piano according to the equal temperament should be equivalent to minimizing the entropy (the physics concept of order) of the generated sound spectrum when hitting all 88 keys at once.
They put this into practice in an equally amazing peace of open-source software (the Entropy Piano Tuner) and made a very good job of explaining it all. See piano-tuner.org/ for the details. I especially recommend reading the software manual, it is a very nice text tying physics and music together.
Trying it out
I decided to test it out on two pianos that are located at our summer house. Neither of the pianos had been tuned for at least 20 years before I started.
I bought this set of gears from www.howardpianoindustries.com/, watched a lot of youtube videos on piano tuning and got to work with the tuning gears, a laptop and USB microphone.
Some relevant facts before you get going:
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A typical piano has around 230 strings, each of which need to be tuned…
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It is amazing how good your ear is of picking up shifts in frequencies that 'sounds wrong'. To get them to 'sound right' though can wear you down.
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People in the vicinity will not appreciate your work when they hear A4 stricken by the umptieth time.
TL;DR it works!
I went from this:
to this:
Of course, a professional tuner will most likely do a better job but for keeping your at-home-piano in shape this will have you covered.
The details
I spent roughly 5-6 hours active time with each piano.
Piano 1 - W Hoffman upright
For not being tuned for more than 20 years, and on top of that being moved to the summer house, it was surprisingly tuned, at least relative itself.
This is how it sounded before tuning:
This was my first ever tuning project and I made the misstake of trying to bring it into pitch in one tuning session. As I mentioned above, the piano was (roughly) tuned in a relative sense of the word but it was still about a quarter note flat.
As many sources will tell you, including the manual to the software, you need to make one or two 'pitch raises' of a piano that is heavily out-of-tune before fine-tuning it. The added tension of the strings will deform the soundboard somewhat and the effect is that the strings that you just have tuned will slacken a bit. The net result of the tuning will thus be that the piano is still flat (although to a lesser extent).
I did not think of that though. Instead I tried to be thorough when tuning the piano for the first time. The result after the first tuning thus ended up being a dissapointment…
This is how it sounded after my meticulous work:
Piano 2 - Hupfeld upright
The second piano was smaller than the Hoffman. It was brilliantly out-of-tune, as you can hear here:
This time, I made a pitch raise, i.e. a not-so-thorough tuning, to get it closer to pitch. This resulted in the following, much better result:
The final result
I ended up tuning both pianos twice, it took me the best part of a week calendar time, both because I found it quite straining to concentrate on getting the pitches correct and thus needed to take breaks and also because my family was not overly happy with the constant 'plonking' of notes.
I am quite happy with the end result considering it was my first attempt. I hear some keys that I would like to adjust further but overall I think it is passable to play the instruments now.
A professional piano tuner could certainly have made a better job and, importantly, much quicker. However, if you use your instrument for casual playing at home, I think the result, especially with a couple of practice runs, is ok.
The table below summarizes sound snippets from how the two pianos sounded in the different stages of tuning.
| Tuning stage | Hubfeld | Hoffman |
|---|---|---|
Before tuning |
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After first tuning |
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After second tuning |
| Tuning stage | Hubfeld | Hoffman |
|---|---|---|
Before tuning |
||
After first tuning |
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After second tuning |