Category — Piano Construction & Parts

The far left pedal on almost all uprights should never be used, shouldn’t even be there. Chop it off and throw it away (some piano manufacturers, thankfully, did that for you, and their uprights feature only 2 pedals.) You see, this pedal tries to simulate the "softening" of the notes as the far left pedal on a grand, even though we already clarified (two posts ago) that the left pedal on the grand is not a "soft pedal," it’s the una corda pedal, not to be used for playing softer. So the left pedal on the upright is trying to simulate an action that shouldn’t even exist on a grand! Huh?

Worse is how it tries to do it. You see, when you push the left pedal down on a grand, the whole keyboard shifts to the right a bit, allowing the hammers to move over and only strike 1 or 2 of the strings where they wold normally strike 2 or 3. It can do this because in a grand the keyboard floats loosely in the piano, and is not bolted down. In an upright, the keyboard is bolted down and immovable, so all the hammers will continue to strike all 2 or 3 strings they always strike. So what did these misguided makers do instead, to try to achieve a softer tone? They put in a wooden rod, worked up & down by the left pedal, that pushes all the hammers about half-way closer to the strings than their normal rest position.

Usually, when you strike an upright key, the hammer travel about 1^3/4" from rest position to the string. Pressing down the left pedal shortens this distance by about half, so the hammer need only go forward about 7/8" before making contact with the string. Less travel or "blow" equals a softer contact and sound, right? Not really. Try it. Hit any key without the left pedal and listen to the volume you get from that note. Now press down the left pedal, and hit the key again with exactly the same amount of force. Pretty much the same volume, right? I defy you to hear much difference. That alone would render it a useless pedal.

But the real problem is that, in lifting all the hammers closer to the strings, the left pedal has effectively thrown all the keys’ touch completely out of regulation, and introduced a gaping empty air-space of lost motion between your finger and making contact with the hammer. Slowly press down any key without the left pedal; feel the firm weight & contact against your finger. Now press the left pedal down, and slowly push down the same key. But wait…whoa! there’s nothing there, no weight, no contact until, ahh, there it is! Only after you’ve pushed the key about 1/4"-1/2" down, can you finally feel the weight of the hammer against your finger. Introducing this severe amount of "lost motion," or no contact between your finger and the hammer (and thus no dynamic control,) all for a pedal that barely achieves its function anyway (softening the volume) was the stupidest invention ever on any size piano. Aaarrggh!

There were a few manufacturers in the early 20th century who added an expensive extra mechanism and set of wooden flanges called a "lost-motion regulator" – A.B. Chase and Vose & Sons pianos had them – but they’re hard to find on any upright piano now, and remember, this upright soft pedal doesn’t really make the notes softer anyway, so once again, aaarrggh…why bother? Just leave one pedal off upright pianos…no big deal! People will still buy ‘em. They have to (see the reasons listed in our last post)

So stare at the 3 shiny pedals on your upright piano and enjoy their attractive three-ness, just like a grand. Then sit down and play, and know that the only one your ever gonna use is the far right damper pedal, period.

 Poor Vertical (Upright) pianos. They are considered the neglected step-sisters of the grand piano. And to some extent, this is not too harsh of a criticism, as their touch and tone is definitely a compromise, and a cut below that of their older grand sibling. No true pianist has any delusion that he or she can get the same sound and playing experience from an upright as a fine grand. This is true even for the taller and higher-quality uprights, for reasons which we made clear in our earlier Feb. ‘09 post, "Upright Pros & Cons."

Still, upright pianos are a necessity in the modern home and school room, because of their compact fit, their easier transportability, and their considerably reduced cost. The majority of home pianos are still uprights, with a 75% to 25% margin over grands. And studio uprights fill the classrooms and practice rooms of even the more prestigious musical institutions. This is a good thing, overall, because it’s forced all piano manufacturers to make the sound and touch of their uprights as "grand" as possible, and has resulted in some significant improvements on the finer uprights.

One of the early attempts to make people think they were getting the full "grand piano" experience from an upright purchase was the sales-pitchy use of a highly misleading misnomer – calling the taller verticals "Upright Grands" in the early 20th century. Upright Grand?? Now there’s an oxymoron if there ever was one, quite like "jumbo shrimp." No, Virginia, there is no Santa Claus, and an upright is an upright, and a grand is a grand, and never the twain shall meet. I still get calls weekly from people asking if I’ll come tune their "upright grand." I ask, "Is it a grand or an upright?" They reply, "It’s an upright grand." I patiently say, "No, that’s just a sales tactic. If it’s a vertical piano against the wall, it’s an upright…if it stands free on three legs, it’s a grand." Sometimes I can feel their spirit sinking over the phone, like, "Damn you for telling me that, it was so much cooler to call it a grand turned upward!" Sorry, it’s not a grand, even though the strings may be as long as some shorter grands. Refer to the link above for more clarity about this.

The other way makers tried to seduce you into thinking the upright was just as "complete" as the grand was to include 3 full pedals, "just like on a grand," even when only one of them performed the same function as it’s grand counterpart, and the other two either feigned similar functions or often did nothing at all! That’s right, on many upright pianos, the middle and far left pedal are just for show!

But on most uprights, all 3 are indeed functional, and here’s how they work:

The damper pedal (far right pedal) works just the same as on a grand, pulling all the dampers off the strings, so they can all sustain freely until letting up on the pedal.

The middle pedal performs a sort of faux-sostenuto function. It lifts only the bass section dampers off the bass strings, allowing the player to hit a big octave or chord in the bass, and have it keep sustaining, whilst they plink short or staccato notes in the upper sections. Not nearly as selective as the grand version, but as we said, there are very few pieces of music written for true Sostenuto pedaling, so it’s adequate.

Modern piano manufacturers, especially the Oriental  pianos, realized this next-to-never usage of the middle pedal for Sostenuto, and decided to assign it a completely different function: pulling a thin strip of felt down between the hammers and the strings (sometimes called a "mute bar") to make your playing extremely soft and muffled, so you can practice late at night, or whenever, without disturbing anyone else in the home. Thanks to the inventiveness of companies like Yamaha, this has now become the more common function of the middle pedal on all uprights.

Next, in "Why 3 Pedals Are ‘2 Much’ On An Upright – Part 2," we’ll take apart (and throw away!) the dreaded left pedal on uprights…

And Why You’ll Rarely Need More Than One

Most modern grand and upright pianos come with 3 foot pedals. Many people are confused or outright mistaken about what they are for and how to use them properly. Let’s start with the pedals on a grand piano, since they are the most "real" and set the standard for what these pedals should do:

Standing in front of a grand piano, looking at the pedals from right-to-left, the far right pedal is called the Damper Pedal. It’s sometimes mistakenly called the sustain pedal, because the end result of pushing it down is that all the notes sustain for as long as you hold down the pedal. Of course, any individual notes that you play will also keep on ringing as long as you hold down those specific keys, but pressing the Damper Pedal lets the notes keep ringing even if you come off the keys.

It does this by lifting all the dampers (hence the name) off the strings. If you remove the music desk from your grand piano and look down over the strings, a few inches back from the tuning pins, you will see a row of curve-shaped wooden blocks with squares or wedges of felt hanging from their undersides, sitting on top of the strings. Now while still staring at these, press down on the far right pedal and you will see them all lift off the strings, allowing the strings to vibrate freely. Let go of the pedal and the dampers fall back onto the strings, effectively muting out any sound.

The dampers are all connected by wires to individual wooden levers inside the piano. You cannot see these levers with the piano all closed up, but if you slide the action out of the piano and look to the back of the cavity where the action usually fits, you’ll see these levers, and a wooden tray that lifts all of them off the strings when you press down the pedal. You’ll see a wooden dowel coming up from under the piano, that attaches to this tray and pumps it up and down. That dowel is in turn connected to your foot by means of a rod and lever under the piano.

The area where the tray and damper levers are secured is referred to as the piano’s "back action," the levers under the piano are referred to as the "trapwork," and the wooden frame holding the pedals and pedal rods is called the "lyre."

Now here’s an important point: In most cases, the damper pedal is the only one you need. As we go on to describe the other pedals, you’ll understand why.

The middle pedal on a grand piano is called the Sostenuto Pedal. You can think of it as a "selective" sustain pedal. The way it works is that you press it down after you hold down certain keys, and it lifts the dampers off (or allows to sustain) just those notes, while allowing you to play the other notes as short, non-sustaining notes, even staccato. So the only time you would need the Sostenuto Pedal is in the rare instance that you want to have 2-8 notes keep ringing, in the bass section for instance, while you play short notes in the treble. There are only about 30 or so pieces in all of piano music that call for that odd pairing of sound – mostly from the more impressionistic and 20th-century composers – so a pianist could go through his whole piano-playing life without ever using this pedal. This is made all the more amazing when you realize that installing this pedal and it’s connecting mechanisms inside a grand piano adds a significant cost to building the instrument, well over a thousand dollars! All that for a pedal you may step on five time in the 50+ plus years you own the piano!

The far left pedal is probably the most misnamed and misunderstood one. It is NOT the "Soft Pedal!" It’s proper name is the Una Corda Pedal; una corda means one string. That’s because when you press it down, the whole key action shifts to the right, just enough to make the piano’s hammers line up and strike just two of the three stings for each note that has a three-string unison, and just one of the two bass strings that have two strings per note. The early 18th century pianos just had two strings per note, and this pedal made the hammers hit just one of the two, hence the the name "una corda."

Now it may be natural to think that hitting only one or two strings for each note, when the piano usually strikes two or three, would make the notes a bit softer, when struck with the same key force, and it does. A bit. A very little bit. Because that’s not the purpose of this pedal. Any good piano instructor will tell you, "If you want softer notes, play softer! Don’t use the left pedal."

No, the original purpose the inventors of the Una Corda Pedal had in mind, was an ethereal sound created by striking only two of the three strings, but having the third string vibrate sympathetically, which it will if properly tuned. This dreamlike sound was their intention, not just a softening of the volume.

Still, you’d be amazed at how many pianists, including accomplished concert artists, use the Una Corda as a "soft pedal," a volume softener, probably because it does make it easier to play at pianissimo levels than simply playing with a more delicate touch…that actually takes technique

In our next post we’ll look at why you should never, ever use the far left pedal on an upright piano, and why it’s even there in the first place!

As we mentioned in the last post, perhaps the most critical component in the piano for determining its final tone and resonance is the soundboard, If there were no soundboard under the strings to amplify their vibrations, the piano would sound as thin as a banjo. Actually, this wide slab of wood under the strings (or behind them in an upright) is usually not one piece of wood, but made up of several quarter-sawn spans of spruce, glued together.

      
We also emphasized the importance of the ribs glued to the back of the soundboard, critical because they hold the soundboard in a slightly convex bowed shape, or "crown." The soundboard isn’t really flat as it may appear, it’s raised slightly towards its middle.  If the soundbaord flattens out and loses its “crown” (which it most certainly will in time – anywhere from 50-100+ years,) the string pressure against the bridge and soundboard will become loose and the tone will suffer greatly.

So the better piano manufacturers use the best quality wood they can find for the soundboard and ribs, and cut & glue the ribs with precision to insure the longest possible life for the soundboard’s crowned shape.

Almost exclusively, the wood of choice for soundboards is spruce. And not just any spruce, but spruce carefully chosen for close grain (for better sound conducting) and that perect balance between strength and suppleness. It must be strong enough to withstand the immense pressure from the strings, but supple enough to vibrate freely with resonant tone.

Piano makers since the 18th century have scoured the world’s finest spruce forests, looking for spruce that would make the most resonant soundboards. An overwhelming majority of this soundboard spruce for American pianos has come from the Sitka region of Alaska. European and Japanese pianos have also used Sitka spruce, and have found great stands of spruce in European forests also.

Because of the immense pressure of the soundboard, as well as wide humidity fluctuations wherever you live, it is not uncommon for soundboards to develop lengthwise cracks in them, often running right along the glued seam between any of the quarter-sawn spans. Henry Steinway once said he’d be surprised to see any of his soundboards over 15 years old that didn’t have a least a crack or two running through them. Although these cracks can look ugly, curiously, they often have little or no effect on the piano’s sound. The overall area of resonating wood is so large, the string vibrations still get evenly distributed over the soundboard despite the cracks.

One condition where soundboard cracks do effect the sound negatively is when the split is not only side-to-side, but where the wood one or both sides of the crack lifts upward, coming loose from the rib below it. Not only can this result in a dead resonance in that spot, but a nasty buzz can occur where the now-unglued rib just barely contacts the soundboard. Often, if you hear a buzz when playing an older piano, most prominent in one section of your keyboard, this loose rib is the cause. Fortunately, it is often a straightforward repair to work some glue between rib and soundboard and draw the two of them together with a screw, which can later be removed

Below we can see some  examples of cracks running through a grand piano soundboard, then across the back of an upright soundboard:

In later posts, we will talk about completely rebuilding older top-name grand pianos, what’s involved and whether it’s truly worth it. It cetainly involves installing all new hammers and damper and other felts, and competely restringing the piano, often with a fresh new pinblock. Many fine technicians know how to do these replacements, and consequently offer their services as a piano rebuilder. But almost none of these have the skill and heavy equipment necessary to replace the entire soundboard of a piano…it’s really a factory job. So it’s critical that each technician measures how much crown is left in the current soundboard, because restoring all the rest of a piano that has a flat or soon-to-be-flat soundboard is certainly a waste of much time and money.

If you stretch a strand of wire, fabric or even gut, to a tight tension, and then pluck it, it will make a sound. Children often explore this by stretching a string between two cans and then trying to talk over the "wire’, or even by just stretching and plucking the rubber band that was wrapped around the Sunday paper.

But the sound created by a wire stretched across thin air, no matter how thick or tight the wire, is pretty thin and soft. Once you stretch the wire across an amplifying body, like a slab of wood, the sound can grow exponentially in richness and volume. This is the theory behind all soundboards – the wooden top of a violin, a guitar, and the large wooden diaphragm spanning every piano.

As in the violin and guitar, the strings don’t actually touch the soundboard, but are suspended just above it, laying across a one or two bridges, themselves made of wood or some other efficient sound-conducting material. When the strings are set into motion, the vibrations pass down through the bridge into the larger wooden slab, the soundboard, which then itself vibrates across the whole breadth of wood grains, producing a deep, rich tone. Piano manufacturers scour the earth for the most close-grained, sound-resonant woods they can find, of which spruce has been the favorite.

Here’s a photo of a full grand soundboard, with the short bass bridge and longer snaking treble bridge already glued into place on top, before it gets installed or strung in the piano:

In order for the soundboard to hold it’s slightly bowed shape (for better resonance and resistance to the pressure of the strings,) angled ribs are glued on to its back:

On a grand piano, you can see these ribs by looking up from underneath the piano. The strings then cross over the bridges, themselves made of a very resonant wood, and the strings’ vibrations are conducted down into the soundboard. As you can see in this photo, the strings arre then wrapped around "hitch pins" on the iron plate to hold them at the back end. On the front end, as we have seen, they are coiled around the tuning pins.

The bridges are just slightly higher than the plane of the string running front to back, meaning that they lift the strings a tiny bit higher than perfectly parallel to the soundboard. This insures the massive downward pressure of the strings. The true contact between the strings and the bridge is further secured by forcing the strings to jag to a slight angle, accomplished by a set of angled "bridge pins" for each note, here seen across the treble bridge…

  And the bass bridge:

Happy and musical 2009!

Over the course of 2008, we looked at this marvelous instrument, the piano, from its original invention, it’s history & evolution, and its pre-eminence as it flourished in the 20th century. Just before the New Year, we beagn exploring all the components of a modern day grand piano in exploded views and cut-aways, so you can see all the piano’s parts from the hugest to the tiniest, and how they all work together. Now that we have a sense of the major structural parts like the case, pin block and cast iron frame (refer back to the exploded view of a grand in our last post by clicking here,) let’s take a look at how this beautiful contraption actually produces sound. What exactly happens when you strike the keys?

Here’s a great animated cut-away view of one key and its connected action parts in a grand piano. Watch closely and you’ll see all the essential movements and connection that take place when you press down any key.

The key rocks on a central fulcrum called the "center rail," and as you press the down on the front end, the back end of the long wooden key lifts upward. This in turn lifts the complicated triangle shaped (sort of) wooden mechanism with all the sticks of wood and springs, called the "wippen." Towards the front end of the wippen, you’ll notice a stick of wood that pushes the hammer up toward the string, called the "jack," by pushing against the bottom of the hammer shank (the stick of wood the hammer is at the end of.) If you look closely you’ll see the top of the jack isn’t actually pushing directly against the hammer shank, but against a little orange-&-white ball hanging under the shank, called the "knuckle." You’ll also notice how the "L"-shaped jack snaps out from under the knuckle at the last moment, just before the hammer hits the string. That’s called "escapement," as we covered in our piano history posts, and that’s what allows the hammer to fall back away from the string, freely, instead of blocking against the string, which would effectively stop the sound.

Finally, you’ll notice that although the hammer bounces back away from the string, it doesn’t fall all the way back down, being caught momentarily at about half-way down by the "backcheck." the red, white and orange cushion sticking up from the back of the key. The orange color is actually a layer of buckskin covering, which grabs the hammer’s tail and holds it in check. This, plus the spring-loaded repetition lever (the top-most stick of the wippen’s "triangle") lift and hold the hammer aloft just enough to allow the jack to sneak back under the knuckle, fully ready for another play of the key, even though the hammer has only fallen back about half-way and the piano player has only allowed the key to raise back up about half way. In other words, even though when playing, the key is pressed down a full 3/8 of an inch before hitting bottom, this marvelous mechanism allows the player to play that note again when the key has only come back up about 3/16", instead of having to let the key all the way back up before replaying the note (as in the earliest pianos.)

Of course, all the springs, sticks and buttons of this mechanism need to be in perfect adjustment (or "regulation") in order for this to work correctly, and that’s where your expert technician comes in. There’s about 15-20 adjustments to be made on each key action! But a good technician knows exactly how to do this. It takes a few hours if the piano is completely out of "regulation," or just a short routine service call if just to keep every part in perfect adjustment. Here’s another detailed view of all the parts in a grand piano action, also showing the damper and it’s respective levers. The damper lifts off the string when you press the key, allowing it to vibrate freely, then comes back onto the string to mute it as you let the key up.

So now we’ve set the string in motion, free to vibrate until either the sounds dies out, or we let up on the key, letting the damper fall back down on the string. Next, we’ll look at the acoustics of how that string’s vibration gets amplified into the room and your ears, through the bridges and soundboard.

Some piano owners just want to play the thing…well, hopefully. They’re too busy being concerned about the functioning of their own fingering and innards, while sitting at the keyboard, to care much about the movement of the springs, parts and mechanisms inside the piano. I understand. The inside of a fine Swiss watch is an amazing interlacing of precision gears and movements, but when I look at my watch, I just want to know the time.

But a modern-day grand piano is made up of some 9000 individual parts, many of them moving parts, and many people are fascinated by how it all fits together and "ticks." These next posts are for you!

First lets take a look at an exploded view of a modern-day grand piano, and talk about the function of each component.

This shows the basic large components of any grand piano, minus the strings and tuning pins (which can be seen in the open-top view on the grand in our last post, The Modern Piano Emerges.)

The S-shaped outards of every grand are referred to as the piano’s case or rim. The straight bar of wood that across the front of the piano, directly over the keys, is called the "stretcher." The wood that closes over your keys is called the "fallboard," and there’s a couple blocks of wood on either side of the keys called "cheek blocks" and a long thin strip of wood just in front of your keys called the "key slip," which round out the main furniture parts of the piano’s case. The stretcher is mortised into the piano’s rim, but the fallboard, key slip and cheek blocks are all easily removable, and you’ll see your technician quickly setting these furniture parts aside if he needs to access the action & hammers. As you can see by the photos above and below, on a grand piano, the keys & action just slide out of the front of the piano like a works-in-a-drawer. That’s important, because although tuning does not require action removal, virtually every other adjustment to the action and hammers does, so the technician has to be able to slide it out often and fast.

We’ll take a look at the works of the piano’s action in our next entry. The soundboard and iron plate that seem to be floating above the piano in the top photo, are glued and bolted down inside the piano’s rim. After the strings are installed, they will pass over the treble and bass bridges and send their vibrations down through the bridges to the soundboard, which is the main sound-amplifying body of the piano. The heavy cast iron plate bears the tremendous tension of these strings (up to 20 tons) so the wooden case doesn’t need to.

If you look close at the front end of the iron plate in the top photo, you’ll see lots of little holes just in front of the red felt strips. You’ll see similar holes in the shelf of wood just behind the stretcher, called the "pin block." These holes line up when the iron plate is bolted down into the piano, and the metal tuning pins are driven through the holes in the plate, down into the wooden pin block, to hold the tension and tuning of each string, as illustrated below.

 As you can see, the inch-and-a-half thick pin block is multi-laminated and cross-grained for a super-firm hold on the tuning pin. That’s a good thing, as the tuning pins don’t "screw" into threads in the wood, but are held just by friction. How? The tuning pins have a very fine thread, giving them a "rough" surface, and they are precisely .010 (ten-thousandths) of an inch thicker than the hole they are being pounded into, when the piano is initially strung at the factory. That’s it! The pin’s just a little thicker than the hole, so it’s tight in there…but they can & do come loose after the pin block has been subject to either significant age (50-100 years) or significant dryness in low-humidity climates.

The top diagram shows how they pass through the holes in the iron plate (the greyish cutaway,) then down through the pin block holes, at about a 7º backward-leaning angle, to further support the immense pull of the string. The string is coiled about 3 full turn around the pin, with the tip of the string inserted into the tiny hole drilled through the pin (see above) called the "becket."

To see how it all fits together, check back to that open-top view of a grand piano in the last post by clicking here. In our next entry, after the Holidays (hope you have a "Grand" season!), we’ll take a deeper look at the soundboard, bridges and action works.