Tuning Unisons, part 2
It is only because my stubbornness outweighs my hubris that I have made any progress at all. My unisons are better after months of practice. The pitches don’t always stay where I put them, but they wander less far, less often. Mark vouched for me, and Schaff sold me a better hammer. Things are going well. However, this morning’s lesson revealed a vexing new problem: some unisons cannot be really, truly, beautifully tuned.
What?! Here’s some background:
We know three strings are in tune two ways: we can either experience the tone color as a sort of gestalt, or we can use our ears to filter out tonal information of the timbre to measure the relationship between the pitches of the two strings. As it happens, a sounding string sings not only its assigned pitch, but also a complex and beautiful family of higher, quieter pitches in the overtone sequence. The volume of these upper partials is what we experience as tone color.
Dear reader, have you already grasped this?! Every note a pianist plays is actually a chord! I had UNDERSTOOD this, in a vague, informational sense, but Mark taught me to HEAR a lively world of overtone activity that had BEEN THERE ALL ALONG and I had only just “tuned in!” Imagine living in your cozy bungalow for thirty years, only to discover one day that there’s always been a second, third, fourth floor!
Tuners train their ears to filter out all but one or two of these upper partials to evaluate the unison. If the upper partials are out of tune, they will interfere with each other and seem to “beat” rhythmically. (Imagine the famous image of the interference of the double-slit experiment, but in sound.) If your piano tone is accompanied by a cacophony of beating and buzzing, your unisons are out. Call a tuner—it’s faster!
Weirdly, the upper partials aren’t theoretically in tune with each other or with the fundamental pitch. They are sharp to various degrees—due to something called inharmonicity, which we had better leave alone for today. All you need to know for now is that inharmonicity can vary based on material, tension, and diameter. And unfortunately, Mark and I discovered that two strings (C3) on my parents’ lovely Craigslist Sauter are “mismatched—” something about them causes their inharmonicity to be different. That means that if the first partial is in tune between them, all the others CANNOT be in tune. Ditto other partials. Yikes.
Mark told me that I could remove the strings and measure them with a micrometer, and then buy new, matching strings. No thanks: I’m still cleaning up March’s mess. The alternative is to tune the two strings out of tune ON PURPOSE, finding the compromise that yields the best sounding results. It will be ok, but it won’t ever be right.
Let me recap:
-Nothing is solid—not the pin, not the hammer, not my perception.
-Perfection sounds shallow, and lacks beauty.
-Every single entity is, on closer inspection, a many-thinged thing.
-It’s worth it to hire a professional.
These are good lessons from 2020. Happy new year, dear reader, and may you enjoy this shifty, squishy, various, beautiful world in new ways each day of 2021.