Cleaning Player Piano Valves

This post is a continuation of the Milton Player Piano Series.

I've been working my way through all of the valves by removing, cleaning, and resealing them.  These are the valves that translate the small openings in player piano sheet music into the striking of the appropriate strings.  Behind each valve is a small pneumatic that, when the valve is closed, the pneumatic has air in it and does not actuate any other parts.  When the valve is open, the pneumatic is exposed to suction which causes it to close and launch the hammer toward strings.

The valves are meant to be airtight, but since the valves are exposed to small particles in the air that are pulled through the player action, it is possible for the sealing surfaces to catch some dust that will cause them to no longer be airtight.  The valves only move about 1/32 of an inch between the open position and the closed position, so even the smallest interference can cause the valve to malfunction.   I have no idea when the last time this player piano was serviced, but there was plenty of air leakage in the action, so I decided to go through and clean the valves. 

 This piano actually contains a double-valve action.  Each note uses two different valves.  The second set of valves can be seen in the photo below.

In this post, I am focusing on the lower set of valves.

The first step is to remove the wooden button that is threaded onto the end of the valve stem.  I use a set of Kelly Forceps to grasp the valve stem while I unthread the button by hand.

Remove the four screws holding the faceplate and set them aside in a way that you will remember which screw belongs in which hole.

The next step is to loosen the glue that is holding the valve to the board.  I do this by heating up the faceplate with a soldering iron.  Hold the iron against each side of the faceplate for 20 seconds to heat it up enough to soften the adhesive.

In order to remove the valve withough damaging the wood behind it, I use a Park Tools Pin Spanner.  The pins fit nicely into the screwholes in the faceplate and allow me to rotate the faceplate in order to break it free from the hold of the glue.

After the glue looses its hold, carefully pull out the valve and separate the faceplate, stem, and leather disc.

Note the guide in the center of the recess.  The back end of the valve stem fits into this guide to ensure it moves smoothly.

Using an old toothbrush, gently scrub the leather disc on the valve stem, as well as the loose leather disc.  Try to remove any traces of dust or dirt.

Additionally, clean any old glue off the back of the faceplate.  A clean surface here is important for a good seal against the wood.  I use a single edge razor blade to scrape it clean.

To reseal the valve to the board, use burnt shellac.  This is simply a thickened form of shellac that you can produce by buying clear shellac from the hardware store and burning off some of the alcohol in it.  Burnt shellac is an amazing adhesive.  It sticks to almost anything and it does a great job when something needs to be airtight.  The only downside is that it can take a week or longer to fully cure, so don't use it for any last minute repairs.

Brush a layer of burnt shellac around the edge of the valve socket.

Reinsert the valve.  Make sure the valve goes in straight, and the end of the valve stem fits into the guide inside the socket.

Reinstall the screws.  Be careful not to overtighten these screws and strip out the threads in the wood.

Finally, reinstall the wooden button.

Now repeat 87 more times!

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A440 vs A432

Over the centuries, the tones that comprise western music have fluctuated wildly. For a long time, there was a lack of any international standard for musicians to tune their instruments to. This meant that every orchestra would tune to a different pitch than every other. An orchestra playing a Mozart piece in Vienna would sound significantly different than an orchestra playing the same piece in New York. Since the 18th century, the keystone of western music has been the note A above middle C, also known as A4. This was the reference note that every instrument in an orchestra would tune their instruments to. The interesting part is that this single note could vary wildly (from 380 hertz to 500 hertz) depending on where in the world the orchestra was. Mozart, Bach, and Beethoven likely composed with an A4 pitch between 420 and 430. Some Italian and French orchestras commonly tuned to a pitch of 450 or higher. If you are unfamiliar with the sounds produced by these frequencies, you can plug them into onlinetonegenerator.com to hear the differences.

In 1953, the International Organization for Standardization set out to create a standard pitch for western music. This standard would allow for musicians worldwide to play the same music at the same pitch. The standard pitch set by the ISO was 440 hertz for the key A4. Though not universally accepted, this standard is by far the most common pitch in use today.

There are many people around the world who oppose the assignment of 440 hz as the standard concert pitch. One alternate tuning that has gained a significant following is 432 hz. A Google search of this frequency will provide hundreds of thousands of links to various websites touting the perceived superiority of 432 hz. Many people have an almost religious addiction to this idea, using words such as “mathematically consistent with the patterns of the universe” and claiming that 432 “will support humanity on its way towards spiritual freedom”, as well as spreading ideas of a Nazi conspiracy to use a 440 hz standard to make humans more aggressive and violent.

A typical image from a pro-432 hz website. This apparently shows the shapes formed when water crystallizes while certain music is played or words are spoken.

One of the most vocal proponents of 432 hz is Brian Collins, who runs the website omega432.com. In order to witness the power of 432 hz, Collins recommends purchasing several frequencies of tuning forks (including a 432), striking them, inserting them into separate glasses of water, and then tasting the water in each glass. This will obviously somehow exhibit the superiority of 432 hz.

Omega432.com also contains plenty of nonsensical babble such as

Saturn completes one precessional Great Year of 25,920 years every 864 of its “years,” a half cycle every 432 of its “years,” a quarter cycle every 216 of its “years,” and an eighth of a cycle every 108 of its “years.” This equals (108 x 30) 3240 years, or 45 degrees of precessional arc. We can continue counting in Saturn years down to 9, one 96th of the precessional year, or 3.75 degrees of arc and 270 earth years, which brings us to the alignment period of the galactic meridian and the zenith/nadir axis.

What all of this number manipulation fails to mention is that the measurement of hertz is a ratio of cycles per second, and that a second is “a measurement of time that correlates with the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom.” Now if that isn't the shiniest, most spiritual thing you've ever heard, I don't know what is.

Another supporter of 432 hz tuning was Rudolph Steiner, the Austrian philosopher responsible for the teachings behind Waldorf Education. Steiner had many strange ideas about music, not the least of which was that the piano was the worst possible instrument for a child to learn. Additionally, he stated

[...] musical instruments are derived from the spiritual world; the piano, however, in which the tones are abstractly lined up next to each other, is created in the physical world by man. [...] A piano is like the Philistine who no longer contains within him the higher human being. The piano is the Philistine instrument. It is fortunate that there is such an instrument, or else the Philistine would have no music at all. [...] Naturally, the piano is a beneficial instrument [...] but it is the one instrument that actually, in a musical sense, must be overcome. Man must get away from the impressions of the piano if he wishes to experience the actual musical element.

Plenty of “experiments” proving the value of 432 hz can be found online. One particularly popular one shows sound frequencies being used to produce patterns in sand on a large steel plate. What they fail to point out is that the “scientist” sabotages the 440 hz measurement by loosening the wingnut in the center of the plate to produce a less pleasing result. 

Experimento de cimática Casero. Home Cymatics experiment with tonoscope. Cimatica esperimento fatto in casa. La ciencia de la cimática demuestra de forma visual el modo en que el sonido configura la materia. La scienza della cimatica dimostra in forma visiva il modo in cui il suono configura la materia.

There are also plenty of instances to be found of 432ers taking the words of French and Italian vocalists out of context and using them for their own purposes. Many of theses famous vocalists have said that higher pitches add additional strain to their vocal chords and contribute to the early demise of their careers. However, what 432ers fail to mention is that these vocalists are usually talking about orchestras that tuned to 450 hz, 460, or even higher. These vocalists were generally not clamoring against 440. The 8 hz difference between 440 and 432 is hardly enough to ruin anyones vocal chords. The difference between these two frequencies can be heard at onlinetonegenerator.com.

I have also read claims that the extra tension required in tuning string instruments to 440 results in “additional strain of tension” and can cause warping and breakage. This claim is equally inane, as modern instruments are built with the purpose of handling the tension of a 440 tuning. In instruments produced before 440 was an accepted standard, this may be a legitimate concern. Of course, these antique instruments should be tuned to whatever pitch they were intended for.

All of these points aside, I have no problem with the fans of 432 hz tuning who simply claim that they enjoy listening to music that uses that pitch instead of 440. That reason is fine, just please cut out the faux science already.

For further reading, I recommend this article from Vice.

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Tuning in the Modern Age

A common tuning fork

Historically, pianos have always been "tuned by ear."  This means that a single reference pitch is tuned to an outside source, then the entire rest of the piano is tuned from that pitch using specific predetermined intervals with known desired outcomes.  In common terms, a piano tuner knows that if an A note has already been tuned to an outside reference, the next higher E (an interval known as a "fifth") needs to be tuned so that only a slow rolling beat can be heard when the A and E are played together.  When this rolling beat has been achieved, the tuner can move on to the next interval, whether it be another fifth, or any other interval with a known desired outcome.

Tuning technology has become more and more sophisticated in the past 300 years.  The first great leap forward was the creation of the first tuning fork in 1711.  Prior to the tuning fork, pitch pipes were used by singers to produce a reference pitch before starting to sing in a specific key.  Although they were adequate for vocal purposes, these pitch pipes had many undesirable characteristics for use in piano tuning.  The brass reeds in them were subject to varying temperatures, humidity levels, and air pressure which caused significant inconsistencies in the tones produced by the single pipe.  The tuning fork solved all of these problems by providing tuners a means to produce a consistently accurate pitch that was practically unaffected by temperature or humidity.  In fact, these tuning forks were so precise that they later became key components in quartz clocks and watches.

Korg OT-120 ETD

Today, in the modern age of piano-technology,  it has become commonplace to encounter successful piano tuners who don't carry a tuning fork with them.  The reason for this is the development and refinement of Electronic Tuning Devices (ETDs). ETDs have been around for a long time (about 80 years!). Historically, they have been very bulky and inconvenient to use in field work, not to mention expensive.  These days, simple electronic tuners are extremely common in the form of small battery powered units used mainly by guitarists, violinists, and players of other string instruments.  When it comes to pianos, however, these units are completely inadequate.  Many guitar tuners only provide a reference for the 6 pitches that comprise the "open strings" of the instrument. Even more sophisticated orchestral tuners are all but useless for range of pitches encompassed by an 88-note piano.   This is due to the fact that these tuners do not account for the inharmonicity present in the strings of a piano.  If you are not familiar with this phenomenon, take a peek at my previous blog post.

The first benchmark in electronic tuning was the development of the "strobe tuner" which was made famous by Peterson Strobe Tuners in 1967.  These tuners provided remarkable accuracy and allowed for extremely minute adjustments of pitch.

An early Peterson Strobe Tuner

Sanderson Accu-Tuner I

Not far behind in production were ETDs made using quartz oscillators, made famous by companies like Korg.  These tuners are very useful for tuning string instruments and come in many different styles with different types of displays.

The first truly sophisticated ETD was the Accu-Tuner produced by Inventronics.  It was produced in the 1980's and was fairly bulky by today's standards, but it was the first device to measure levels of inharmonicity and to be able to compensate by offsetting the desired pitches by appropriate amounts. Following the Accu-Tuner were several other advanced tuning systems such as the Cyber-Tuner and the Verituner.

The main page of TuneLab showing the Phase Bar and frequency graph

Today, these bulky machines have been widely replaced by software products like TuneLab.  This program can be installed on any computer or mobile device and will use a device's built in microphone to provide visual feedback during tuning.  A "Phase Bar" as well as a frequency graph are displayed to give the tuner multiple ways to view the same information.  Tunelab can also be used to record "test notes" along the length of the keyboard, calculate an instrument's inharmonicity, and produce "tuning curves" that the tuner can manually customize to produce any desired result.  Also available is an "Overpull Mode" that calculates the amount that each string must be raised over the target pitch during a pitch raise in order to be left with an approximately in-tune piano after the pitch raise is finished.  Limits are set into the mode to prevent any strings from being raised sharp enough to break.  Using the frequency graph, a successful pitch raise can be performed without having to mute a single string!  At first, I was quite skeptical about the program's ability to use a smartphone's microphone to produce satisfactory results, but I can say that it is quite remarkable how consistently accurate it is.

TuneLab's Overpull Mode settings

TuneLab can be downloaded here and can be used in trial mode for free.

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Between the Liner Notes: The Tuning Wars

As a follow up to my recent book review of Stuart Isacoff's Temperament: How Music Became a Battleground for the Great Minds of Western Civilization, I'd like to share a podcast from the folks over at Between the Liner Notes. The episode is called “The Tuning Wars.” In the episode, the host, Matthew Billy, interviews Stuart Isacoff who elaborates on various aspects of the book.

Billy begins with the effect that Temperatment had on the public immediately following publication. People across the world lashed out at Isacoff, attacking him via blog posts, tweets, and Amazon reviews. One opponent may have even gone as far as comparing Isacoff's language to that of the Third Reich. To many, the issues discussed in Temperament are far from resolved and these people took Isacoff's claims as an attack on their beliefs.

The most interesting part of the podcast is when a portion of a Bach composition is played with several different tunings and in different keys: first with Pythagorean tuning and in a key that the piece was not intended to be played in, second with Pythagorean tuning and in the key that the piece was intended for, and finally in Equal Temperament.. Here, the listener can actually hear what Isacoff's entire book is dedicated to describing – the “wolf” intervals, the beautiful harmonies, and the compromise between the two. In addition, Billy describes the origin of the word “temperament” and its relation to the system of medicine known as “humorism” common to ancient Greek and Roman societies.

The Catholic Church was fiercely loyal to the Pythagorean tunings. The Church believed that the “godly” whole-number ratios that formed consonant musical intervals were a gift from Christ himself and were not to be tampered with. At one point, there was even a “Battle of the Organs” in which two leading organ-builders with differing opinions on temperament competed for their instruments to be permanently installed in London's Temple Church. Calling it a “battle” is only a slight overstatement, as one side went so far as to sabotage the other's organ the night before the contest.

Many famous names were involved in the battle of Equal Temperament. Galileo's father, Vincenzo Galilei, had a long and bitter dispute about the topic with his teacher Gioseffo Zarlino which often devolved into one attacking the other's character. Isaac Newton and Johannes Kepler respectively claimed that the intervals of western music were proportional to the distance between colors in the spectrum of light and between planets in the solar system. Kepler went as far as to attribute male qualities to certain intervals and female qualities to others.

Between the Liner Notes does a fantastic job of expanding on some of the most interesting points from Temperament. I highly recommend listening to the podcast in full and am looking forward to their next episode this coming Monday.

Listen to the full podcast here:

http://www.betweenthelinernotes.com/episodes-1/2015/9/1/02-the-tuning-wars

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Cleaning Out an Upright

If you own an old upright piano, every few years, you ought to open up the base of the piano and take a look. Often times you will find rodent nests, broken pieces of the piano action, decades worth of dust and old pencils, or anything else you can imagine. This process only takes a few minutes and can give great insight about any ailments that may be affecting your piano.

I was recently called out to diagnose an old spinet that had survived Hurricane Katrina. The water had risen a few inches above the floor of the house and the water line could still be clearly seen at the lower end of the cast iron plate inside the piano. The reason I was called in was because, in addition to the piano being out of tune, many of the keys were either sticking or just moving very roughly. The first thing I did when arriving at the owner's home was to remove the lower panel of the piano (looking for a clue as to the piano's history). I saw the water line on the plate, but I also saw what looked like small piles of cat food along the bottom board inside of the piano. To me, this immediately implied a past or present rodent infestation. At some point, these critters had made this piano their home, found an open bag of cat food, and had stashed some of it for later. This definitely gave me an inkling as to what was going on with the keyboard. There is usually large enough gaps in the keyframe under the keys for mice to squeeze through and move around underneath the keyboard. However, this inkling didn't fully prepare me for what was to come.

After my quick check inside the lower cavity of the piano, I decided to pull a few keys out of the piano to see if there was anything underneath that could be jamming them, as well as looking at the condition of the bushings inside the keys that usually allow it to move smoothly up and down. After removing the top panel and fallboard, I lifted a few keys off the keyframe. What I found was that during the storm the mice that had been storing their food in the bottom of the piano needed to look for higher ground and, finding the cavity underneath the keys, had completely packed it with partially chewed cat food. The entire length of the keyframe had served as their emergency food storage. The food was so tightly packed and stuck together that it had to be chiseled out with a spoon and screwdriver.

The piano's owner and I spent a little over an hour removing all of the keys (and numbering them to ensure they were replaced in the proper order), scraping, scooping, brushing, and vacuuming all of the cat food out of the keybed cavities, and replacing the keys. Once the keys were back in, I was able to play all the way up and down the keyboard with only two keys showing any signs of sluggishness. These were quickly remedied by slightly easing (compressing) the balance rail bushings inside the offending keys.

This piano provides a great lesson about being vigilant about maintaning your piano. Open up the lid and the bottom panel every once in a while and take a look inside. If you see broken wooden parts, missing screws, or piles of small debris formed by rodents, you should take action quickly to prevent any small problems from becoming a serious issue that will prevent your piano from having to undergo expensive repairs. If you find that there are rodents moving in and out of your piano, be careful when cleaning up the mess they leave behind. Rodent feces can contain harmful viruses, so you should wear a dust mask and gloves. If you think they have caused damage to your piano, call your local piano technician to perform repairs and advise you on how to prevent similar damage in the future.

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