[pianotech] How to analyze an existing tuning

[Paul McCloud]

Hi, Mark:
I assume that's your name, since you didn't sign the post.
I would guess that it might be a different answer depending upon whether or not one uses an electronic device to tune the piano.  Using an electronic device, one measures several notes to determine a stretch factor, or an inharmonicity factor, and then depending upon the device proceeds to tune according to the instructions for that device.  Usually, it consists of starting from the bottom note to the top, but it varies.  There is no reason to analyze the piano in any particular fashion, other than to see if there are some notes that are way off, compared to others, which might indicate that the tuning pin is loose and not holding that string in tune.  Or for some other reason of sticking keys, etc.
Unless there is a situation where one has recently tuned the piano, such as in a concert or performance instrument, I really see no reason to have to analyze whether this particular string/pin is stable or not.  Most likely it isn't, which of course is why you're there.  
The forces on the piano, such as the temperature and humidity, and time, conspire to degrade the tuning.  I often find that a note might tend towards the flat side, and if I put some pressure on the tuning pin in the direction of flattening the note, it drops in pitch dramatically.  In that case, I figure it's probably just friction that has held the string from falling as far as it did.  But, that just means I'll likely have to raise the pitch before I tune it.
All of the electronic tuning devices have some kind of measuring ability, and/or dedicated function for raising the pitch, after which one would do a second tuning pass to fine tune it.  Most often, this is required for a piano which has not been tuned regularly, and so I ask the owner when it was last tuned.  If it hasn't been tuned in the last year, I inform them that a pitch raise might be necessary, and the extra cost for that.  I don't want to surprise somebody with a bigger bill than they might expect.
For my own curiosity, I might play some notes or intervals, like 5ths for example, in the low tenor to see what it sounds like.  The low tenor of the piano more sensitive to temperature and humidity, and the pitch of the notes there changes more drastically than other areas of the piano.  The reason is that the tension on those wires is generally lower than in the bass or high treble.
If one is inspecting a piano for sale, one might sample various tuning pins to see how tight they are.  I usually try to tune the unisons of random notes, paying attention to the shape of the pin block and where it thins.  It's more likely to split there because there's less wood surrounding the pins in that area.  On most pianos, it's in the lowest tenor notes.  
If one is an aural tuner, one might be more concerned about the overall pitch, and overall relative pitches in various parts of the scale.  As I said before, one might find that the lowest tenor notes are particularly off, sharp or flat, in a consistent manner.  I would attribute this to raising or lowering of humidity.  I would want to be aware of that before I pull out my tuning fork to tune the piano.  Of course, I'd check the A note with my fork, to see how close it is to 440cps.  It would determine whether I am going to do a quick tuning to raise the pitch or not.  In a pitch raise, there is no urgent need to try to fine tune, so it is generally done quickly.  As one is doing the actual tuning, one might discover various anomalies in the various tuning pins, some tighter or less so, or even some that are almost borderline to hold the string in tune.  Other than putting the tuning hammer on every note, there's no way to know whether they are holding or not, or what condition they may be in.  Signs of pin doping around the tuning pins would give me a hint that perhaps the pin block is failing, and some other tech has tried to remedy the situation without replacing the block.
If, for example, one finds that a particular note has clean unisons, and it is in perfect tune, I might or might not test the note to see if will stay put.  Maybe I'll give it a hard blow, or put my hammer on it and see if it tends to move to the flat side.  I don't want to depend upon friction that may be holding it there.  Ultimately, one has to use the tuning hammer to test the pins if one wants to know how stable the note is.  
Another factor is one's technique in setting the pins.  I like to leave the string/wire is a balanced state so that there is a small amount of reverse twist on the tuning pin to balance the pull of the string.  I'll test that by nudging the tuning lever on both directions to see if the string tends to go sharp or flat.  I use a Accutuner, which shows clearly the tendency in either direction.  Over many years, my technique has produced very stable tunings.  A common procedure of tuning requires a strong blow to test whether the string/pin is stable.  Less experienced techs might rely upon a sharp blow to impose their "will" upon a piano string, and later find that these very strong blows did not make the string stable, but that the piano later moved sharp.  I found this out in my early days of tuning, especially in the high treble area of Steinways where tuning is more touchy and difficult to make stable.  Steinways in particular are a little more challenging because they don't use tuning pin bushings, and "flagpoling" of the pin is more likely.  (Flagpoling is the bending of the tuning pin, like a flagpole.  The bushings help prevent that)
There might be other potential indicators of structural problems related to tuning, such as glue joint failures in the back posts where they are joined to the pin block under the lid.  You can see this often just by opening the lid and looking at the top of the block.  It might be covered with a strip of felt or thin plywood.  In rare cases, the whole pinblock might be loose, and the piano won't work at all.  Or, the plate might be broken and many notes in a certain area are way out of tune.  
These are the things I do to assess the condition of the piano, but I might not always do every test before I tune.  I'm going to find out in the tuning process where there might be problems.  I will always ask the owner if there is some particular concern or symptom that I need to address, such as sticking keys, or circumstances like moving that would have affected it.  If it hasn't been moved, and the piano was tuned within the last year, I don't expect it to be wildly out of tune.  If it is, I might try to ascertain why.  Maybe it's really flat, and the last tuner tuned it to itself.  I look for clues to why the piano is or isn't in tune.
I hope this answers your question.  I'm sure you'll get some more responses.
Paul McCloud
San Diego

----- Original Message -----
From: "Mark Davis t/a PianoForte Technologies" <pianofortetechnology at saol.com>
To: pianotech at ptg.org
Sent: Wednesday, December 19, 2012 1:48:23 AM
Subject: [pianotech] How to analyze an existing tuning


May I ask you folks how you analyze a piano before you tune it, your procedure? Also in particular I would like to know how one analyzes, for example, each tuning pin/string of a note though that particular note is showing/sounding as a clean sounding octave and unison? Though it sounds good, how does one analyze/test each pin & string to make sure it is actually solid & stable?