What a Coincidence!

I would like to start this one by pointing out that my intentions with these blogs isn't to overwhelm those who read them with a bunch of piano technobabble. It's the opposite actually... I hope to be able to try and translate much of what we do into a more easily understood language... not just to inform piano owners, but to attempt to attract new people to the field. So when I tell you that doing this with the meantone tuning blog was quite difficult, please realize that this one... DOUBLE DIFFICULT. Today, we are going to talk about what is known in the piano technician world as partials.

If any of you are tuners/technicians, and you discover I said something wrong or could be misread, please be civil in your response. Executing me for my crimes before putting me on trial serves no one. That being said, here goes nothing:

If you thought piano tuning was nothing more than a tuning app and a ritual to the piano gods, you've either only ever had novice tuners or you've been misinformed. Don't get me wrong... ETD's and ETA's (Electronic Tuning Devices or Apps) can be very helpful. I don't shy away from their usage, though there are plenty of puritan tuners out there who would see their usage as blasphemy. But, in truth, that usage should really be minimal. The technology is great, but it is still not perfected. There's just some things that the human ear can detect that artificial methods cannot. The reason is due to the wide variety of "personalities" a piano can have. Things that an experienced/professional piano tuner can pick up on as they listen to your piano. Much of this comes in the form of coincidentals... or tones from one note coincidentally matching tones from another. I can be a little sentimental sometimes and through that sentimentality, I tend to see this as the piano's voice... it's way of talking to us. Coincidentals occur when a partial from one note lines up closely with the partial of another note... hey... I see your eyes already glazing over. Don't worry, just keep going and I might succeed in this.

Now, there's a handful of frequency mathematics involved in talking about coincidentals. In fact, I sometimes tell people there's some calculus involved and that's just slightly true. Calculus goes into some deeper theory, but the math involved here just barely touches calculus: It's ratio and wave theory. Mathematicians... have fun. As I mentioned in a previous blog, I despise math. But, I love piano work so much, that I have actually put in the effort to try and understand it... and it's safe to say, I get the gist. But, I'm not going to explain it to you in ratio and wave theory as far as frequencies go. Instead, I'm going to use something much more tangible to the everyday piano owner: the strings.

Let me start by asking you to look at the strings in your piano. If you have a grand, it's much easier to do. If you have an upright and don't really want to open it up as you haven't had your coffee yet, I'm sure there's pictures online somewhere. You'll notice as you look at the strings that each note has multiple strings for it. If it's in the treble (right side of piano) range, it likely has 3 strings for each key. If it's in the bass range, it may have 2 strings, and even 1 string for the lowest of the low. For now, let's focus on the 3 string keys, known as tritone notes. If you were to put your finger on one of the 3 strings and trace it to it's origins and destination, you would see that the one string starts at a pin, goes down into the piano, hooks, then comes back up to reach the second pin. Depending on which string you traced, it either hooks to the second pin of the key, or the first pin of the next key. Regardless, the point is that 2 strings are actually one.

Now... knowing this is where partials and coincidentals come into play. While it usually refers to frequency vibrations, it works just as well with the strings. In the treble range, tuners will tune to a 4:2 coincidental. That is to say (please bear with me and don't gloss over yet) the 4th partial of the first note is equal to the second partial of the second note. Take that string that is pretending to be two strings: If I, as a tuner, was to mute the first string of a tritone note at the halfway point, it would actually be getting muted at a 4th of one string... the 4 in the 4:2 partial. Without being muted, only half the string is muted down at the hook. If I were to take a pick and pluck the string with it be muted halfway down, the tone it would make would be the same tone as the note one octave above it if only one of the 3 strings was sounding. That one string is half a string... the 2 in the 4:2 partial. These two tones sounding the same... that's the coincidental. Mute half way down one string on C4 and mute two strings on C5. Pluck C4 and play C5... same tone!

Did I succeed? Did you understand it? If you didn't, I'm so very sorry. I did my absolute best for a topic that can get incredibly complicated. If you did understand it, then let me leave you with one more awesome factoid about coincidentals: When the tuning of all the strings is done, a tuner can test how well they did by one more coincidental sound. Playing two notes that are a third apart (two whole steps) will have an undertone that rings out the same tone as the octave above the third. You'd have to listen closely for it, but it's there. For example: Playing a G# and a C will have an undertone that is the same tone as the C in the next octave. What a coincidence!

So, to wrap, you might be wondering how this determines the personality of a piano or acts as it's voice? These coincidentals aren't exact. In most, if not all pianos, the tones are just a touch sharp. How sharp they are is where the nuance exists that human ears need to listen for instead of artificial ones. Hope you found this informative and as always... Stay tuned!