Another great question that I mostly addressed in my second post in the section titled:

Shouldn’t a good “master tuning” last for several years?

That article gives a good explanation of what is happening inside the wood when it is subjected to moisture changes.  However, in addition to the information there, I want to focus in this post on some practical evidence of humidity change, as well as give some “real world” examples why the idea of a “forever tuning” doesn’t exist, except in our dreams! 

I’m pretty sure that everybody that owns a piano secretly wishes for “the tuning” that would last forever.  (For the record, we piano tuners don’t, by the way!)  Ok, let’s turn the tables for a minute….whenever I leave the doctor’s office, I always secretly wish that it would be the last time….though I know it won’t.  I guess we’re all wired that way.

Anyway,  back to pianos….IF pianos went out of tune just due to use, then it would make sense that if the piano were never (or rarely used) that it would maintain it’s tune until it had been played enough to “bang” it out of tune again.  Unfortunately, that is not the case with pianos.  In fact, I don’t think that’s the case with most things in life.  Our world is in a constant state of change.  Consider the weather, the water cycle, the rock cycle, the human body, the seasons, and the list goes on.  With all this change going on all around us, both in things we see, as well as within the microscopic world that we cannot see, it only makes sense that the objects around us are also in a constant state of change.

If you stop and think about all the things in life that change, move, or shift because of aging, vibration, humidity, dryness, sun’s radiation, etc, we could fill several books listing the many things that don’t stay constant in life….yes, most everything!  Some simple examples: A bolt, unless rusted on, will usually loosen over time if subjected to heat, cold, vibration, and such.  Doors once oiled will begin creaking when the oil seeps out of the hinge and/or dries up (even if the door was never used).  A child’s swing-set sitting out in the yard will begin to fade and the metal will rust over time, even if it was never used…ask me how I know?  I have a package of assorted rubber-bands in my desk drawer right now that I’ve had there for many years.  Many of them are still good, but some of them have dried out to the point of breaking with one use.  So, you can see that natural forces are constantly at work on the objects around us, and our pianos are no different.

Practical Effects of Humidity (moisture) on Wood:

The piano, being primarily made of wood, is susceptible to the effects of humidity.  The wood will move, swell or shrink, even before our very eyes if given enough moisture or dried quickly enough. 

Try this: soak a large wooden tongue depressor in water for a few minutes, lay it out on the table for a few minutes and see what happens, then dry it with a blow dryer.  I haven’t done this, but I can only imagine the warping, curling and such that would likely be evident.

What about a piece of cardboard?  We all know what a nice, new piece of cardboard looks and feels like.  We also all know what a wet, warped piece of cardboard looks and feels like.  Furthermore, after that wet cardboard dries out, it will never be the exact shape it originally was before it got wet.  I like to paint sets at our church for church plays, etc.  I’ve learned that if you paint only one side of the cardboard, when it dries it will curl considerably toward the painted side.  My nice straight cardboard walls become bowed looking walls that don’t stand up straight anymore.  All from the effects of humidity.

If you’ve never done this, it’s kind of fun.  First we need to agree that paper is wood, correct….very, very thin, but made from wood no less.

Now, next time you tap your restaurant drinking straw on the table to take the wrapper off, be sure you’ve scrunched the paper up pretty tightly like an accordion before taking it off the straw. Now, lay the scrunched paper down on the table, take only a drop of water and place it on the wrapper.  It will begin growing and stretching out like it is alive.  While this is a fun little experiment that shows the effect of moisture on paper, it may seem a little overly exaggerated as it relates to the actual parts of a piano, but here again, maybe not so much.  The little drop of water had a huge effect on the wood fibers in that little piece of paper, yes. Now what would happen if you had a whole ream of paper and the same drop of water?  On the flat surface of the ream, probably not a huge effect, but on the end of the ream where it could penetrate in a little, I think there would be a noticeable change. This same drop of water, in reality, could have a significant effect on a wooden piano part much the same way.

Again, for a detailed explanation on humidity, refer to my article “When Should My Piano be Tuned?”

Just because we don’t see water in the air, doesn’t mean it’s not there.  Case in point.  Our church runs a dehumidifier in the fellowship hall.  On most days when the humidity is above 50% or so, that dehumidifier can pull more than a gallon of water out of the air in a single day.  Note, that that’s just one dehumidifier running, almost non-stop, and still not bringing the humidity down to proper levels sometimes when the room humidity is high.  Therefore, a couple dehumidifiers would probably pull out twice that much or more.  That’s a lot of water in the air.  Remember, now that the wood cells are tubular like a bundle of drinking straws, just waiting to absorb that moisture.  When it does, the wood moves, and when the wood moves, things go out of adjustment…including tunings.

I read about a funny story (true story by the way) about a technician who was called to repair a string on a piano, but according to the customer, he “had to replace the string without turning the tuning pins”.  When the technician asked why, the owner said that the piano kept going out of tune so often that they hired a “master tuner” to do his best “master tuning” on the piano.  Then when he left, they poured superglue around all the tuning pins, thinking that they were “cementing” that tuning in place once and for all.  The customer was wrong on two accounts…1) the super glue will not cement the pin in place permanently, and 2) even if it would, the soundboard and bridge are both made of wood, and they swell and shrink more than the pin block, and are the main reason pianos go out of tune due to humidity changes anyway.  The tuner, I’m told, waited until the customer was gone and proceeded to replace the string as normal (by the way, there is no way to replace a string without moving the tuning pin!)

So, just because you don’t play your piano much doesn’t mean it won’t need a tuning now and then.  As sure as the seasons change, your tuning is changing too.

You ask, what do you do to combat the humidity changes in the piano?  While there is no perfect, low-cost solution, here are a few things that can be done help control humidity.

– Dampp-Chaser Humidity Control System (system installed in piano)

– Room humidity controlled (not just by house system, although those can sometimes help)

– A humidity controlled storage unit (like some schools or other performing arts buildings  have back stage)

– Use a cover over the piano when not in use, and an undercover (especially when used with a Dampp-Chaser Humidity Control System.

In summary, there are no “forever tunings”, so might as well make friends with your local piano technician, you’re gonna need him!

Until next time…Make a Joyful Noise!