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Posts tagged damper

The Sostenuto Pedal

Piano Price ~ November 2017
Chapter Index

The Sostenuto Pedal

Sostenuto-piano-pedalThere has never been said any words in the piano industry that are more divisive than “But does it have a middle pedal?” Why are these words divisive? Because the middle pedal on the piano is the least used and yet most focused on in the piano industry. I’ve often told the story about one of the greatest jazz pianists in my city, when he was just signing the papers to purchase a beautiful grand piano, he stopped and turned to me and said, “Glen, I’ve just got to ask… What does the middle pedal do? I get asked because I’m viewed as the professional and yet I don’t even know and I’m too embarrassed to ask! Can you please tell me?” We both had a bit of a laugh because he’s an incredible professional musician who has existed for decades without even knowing what it does. After technically showing him he then said “When would anyone use that?” Precisely my point.

The middle pedal on the piano, if you would break it down into frequency of use might possibly be 98% for the right pedal, 1.9% for the left pedal and maybe (if you’re lucky) 0.01% for the middle pedal. The right pedal, the sustain (also known as the damper pedal) is used with every musician and every player because it lifts the felt dampers and sustains the notes and keeps the strings resonating even after we have lifted our fingers. In essence it “fills in” the sound. The left pedal, the “una corda” pedal changes the dynamic (volume) level of the piano and/or the timbre of the tone – making it the soft pedal. But the middle pedal… ahhh yes the infamous middle pedal has been known to have 5 different usages.

In this article, we’ll take a look at the advantages of the middle pedal and why it’s not the best decision to judge a piano based on this non-standard device.


Pianos equipped with the sostenuto function are what I would call “selective sustain”. While the right pedal sustains all the notes, the sostenuto, in essence holds down selective notes you wish to sustain. I love how this chap in the U.K. both demonstrates and performs on the piano utilizing the sostenuto pedal (video to the right). He beautifully shows both the function and form of the sostenuto.

Bass Damper
As you could see in the sostenuto video, most of the time, the sostenuto pedal is used to sustain the bass notes. So why not make a pedal that just sustains the bottom notes? Some manufacturers decided instead of offering a sostenuto pedal (which is more labour intensive in manufacturing) they would offer a type of split sustain. The middle pedal would then act like the a sustain pedal for just the bass notes.

Practice – Mute – Celeste

Herein lies the big departure for the middle pedal as it has absolutely nothing to do with sustain at all and yet can be found in most modern upright pianos today. It is called the practice pedal, the practice mute or the “celeste”. The purpose on this middle pedal is to reduce the volume of the piano by sandwiching a thin layer of felt between the hammers and the strings. Take a look at this 10 second video and you’ll get the idea. This is neither a sostenuto nor a bass damper. It doesn’t function like the above pedals. It simply is meant to mute the entire piano (much more than the soft pedal).

Silent Pedal
With modern manufacturing, the middle pedal has also been used as the silent pedal while simultaneously engaging an electronic device to allow you to listen to your piano with headphones. Known as “silent” or quiet option, the middle pedal blocks the hammer from striking the strings. What you will hear then is a slight knocking from the hammer shanks (the “handle” of the hammer) against the silencing rail. Underneath each of the keys are infrared sensors that determine what notes are being played and transmit signals to an electronic device which makes the digital piano sound come out of headphones. For night time playing or extreme privacy, these pianos are brilliant.

Steinway-diary-1874Novelty or Nothing?
I have to admit (and am thankful to say this) but I haven’t seen a “novelty” brass tack rail for many years. Similar to the practice mute pedal, the novelty rail lowers a series of brass tacks in between the hammers and the strings and makes the piano sound like a honky-tonk piano. Alternatively, I’ve also seen pianos that are connected to… nothing. Nothing? Yes nothing. Why would a piano have a middle pedal connected to nothing? The answer is simply that customers wanted a third pedal. Cosmetically, it may have satisfied some consumers but opening up the piano I have on more than one occasion seen pedals with no function whatsoever. They’re pretty rare though, but provide a bit of a laugh when you’re asked to fix the middle pedal.

Steinway-patent-1875Today’s manufacturing world mainly has evolved to having a standard sostenuto pedal on grand pianos and a practice mute pedal on upright pianos. Regardless, it’s probably not the best choice to base a piano decision on the middle pedal. As a friend of mine once said “it’s like buying a car based on the radio antenna”… referring to the obscurity of use.

History of the Sostenuto Pedal
According to Fred Sturm in his paper “The Invention of the Sostenuto Pedal”, he writes that pianos used to have many pedals (upwards of 7!) during the early 1800’s when there was more experimentation around the piano. The sostenuto pedal was patented in France by the Boisselot brothers in 1843-1844. “Sons soutenus” simply translated means “sounds sustained”. After another piano maker, Montal exhibited pianos with this pedal function in the mid 1800’s World Expositions, this invention was given more exposure. Fast forward to 1874, a patent was presented in the U.S.A. by Mr. Waldo Hanchett. In his diary (shown above), William Steinway commented after viewing this invention that it was splendid. After some legal and patent disputes, Steinway re-designed the pedal and forwarded a patent in 1875 for the sostenuto mechanism as we know it today. If you have the time, check out Fred Sturm’s paper – a fascinating read.

Practical Application of the Sostenuto Pedal
As previously mentioned, the main idea is usually to sustain lower notes while changing chords in the upper register. When you depress lower keys and then press the sostenuto pedal, they create a foundation of sound from which you can then superimpose other chords on top of without affecting the selected lower notes. But what happens if you don’t have a sostenuto pedal? What if you have an upright piano with a practice mute? The work around is that you can get a similar effect by half pedalling the sustain (right pedal). Since the lower notes vibrate with greater energy than higher notes, if you half pedal – meaning that after you depress the sustain pedal, Victor-Borgeyou only come up until the dampers slightly touch – you can still keep the energy of the bass strings and clear the top notes. It’s not a true sostenuto but it accomplishes a similar effect for the rare times that it is needed.

To conclude, I’ll leave you with my all-time favourite quote about the middle pedal which comes from the comedian/piano performer Victor Borge who said “You know, some people have asked me why there are three pedals on these grand pianos..Well, the pedal in the middle is there to separate the two other pedals…which might be bad news for people with three feet.”

Musical and Mechanical Basics of the Sustain Pedal

Piano Price ~ March 2017
Chapter Index

Musical and Mechanical Basics of the Sustain Pedal

I remember teaching my kids how to drive a car. At first it’s a bit daunting putting a young adult in a 2 ton vehicle controlled primarily by a gas pedal. Over time, the confidence and competence increase. What remains somewhat of an accepted disconnect, however is HOW that process works. You put your foot on a small pedal and ‘magically’ the vehicle moves. Similarly, piano pedals are like that: if you step on the sustain pedal (the right pedal), the sound of the piano is transformed. Today, we’re going to delve into a bit more of the mechanical side of the damper pedal in hopes that awareness will clarify what happens when it is being incorporated into piano playing.

Arthur Rubenstein describes the sustain pedal as “the soul of the piano”
Blue tooth player piano
The use of pedals to add expression dates back as far as the late 1700’s. The question is: how does the sustain pedal bring about this expression or as Rubenstein called it, the soul? What were the makers of the piano searching for to make this percussive instrument more lyrical? Interesting are some of the earliest renditions of levers controlled both by hand (see picture) or knee (placed under the keyboard). Blue tooth player pianoErgonomically, neither of these methods proved successful or efficient. While it’s difficult to attribute the sustain pedal to one maker (as the piano was being developed simultaneously by several makers in different countries), probably the most renowned maker to create a standard foot controlled pedal was John Broadwood. Composers such as Beethoven started pedal markings in their manuscripts to translate the concept of sustain pedal. Historically, when we look back on piano makers and composers, they were attempting to make an effect that would ‘smooth out’ or connect notes played by percussive hammers.

The limitation of a percussive instrument: Strike a bell with a mallet and it resounds until the natural vibration decays and it is inaudible or alternatively you stop the vibration with your hand. Piano strings are the same – strike them with a felt mallet (called the hammer) and they would continue to resound if it weren’t for damper felts (see the article with Laoureux on the making of damper felt). Dampers sit snugly against piano strings until a key is depressed. Upon playing a key, an individual damper is raised from the string, allowing it to sing. Blue tooth player pianoLifting your finger, the damper returns to the string and terminates the sound. So what’s the limitation? It’s not so much the piano as it is a factor of human inability to depress notes quickly in succession. When you try to play without pedal, there remain small gaps between the notes when we play. The sustain pedal then is the mortar to the bricks. (Thank you… no applause necessary. That’s my own illustration of how the sustain pedal works). Think about a brick wall – the substance is the bricks. They represent the notes being played by our fingers. In between, is the cement we know as mortar which fills the gaps and connects one brick to another. In slow motion what is happening is that when we depress a key on the piano, the damper (felt) block comes off the string. When we need to move to the next series of notes, our fingers start to move but we need the note to… (wait for it)… sustain a little longer while we transition. The addition of the sustain pedal (also known as the damper pedal) then allows complete lyrical freedom to move our hands without the compromise of the tone escaping. The sustain pedal holds those notes until a new series of notes are played.

The sustain pedal is so much more, however. When all of the dampers lift, the sympathetic vibrations of all of the strings also resound. As an experiment, depress the sustain pedal and sing a note. What happens? The piano “echoes” or excites the vibration of the frequencies on all the strings. When the sustain pedal is played, it connects one note to another, yes but it also adds the fullness of tone. You can play a chord on the piano as loud as you can but when you add the sustain, it sounds thunderous. At other times, special effects such as flutter or half pedal shade or color the tone like an impressionist painter blurring the lines.

How does the sustain pedal work? How does the gas pedal make the car go? First let’s define the parts and then we’ll

explore how each part is integrated into the system. As previously mentioned, the dampers are the felt (and blocks) that rest on the strings. Pictured to the right you can see the dampers moving up and down against the strings.

In the up position, the felts allow the strings to vibrate freely. When they go down, the damper felts mute the strings and stop them from resonating. Second, (pictured in the middle) the dampers are resting on a common rail (also called a damper tray in grand pianos). What’s shown here is the inside of a grand piano. At the top of the picture, you can see the dampers from underneath the strings and the dampers lifting. Upright pianos have a rail but the principle is the same. Third, the trapwork (pictured at the bottom) is the lever system that simply joins the rods to the pedal lyre (on a grand) or the pedals at the base of the piano (on an upright). When your foot depresses the pedal, it pivots on a fulcrum like a teeter totter or an office stapler. Did I just lose you there? On a grand piano, when you press your foot down, the pedal pivots like a teeter totter – the front goes down and the back end of the pedal goes up. Upright pianos also emulate that OR they have an alternate stapler approach – the pedal fulcrum or pivot point is at the back (like an office stapler) and the pedal is simply pushed down. Either way, when the pedal is depressed, the pedal rod is pushed up. The rod engages the common tray or rail which lifts and activates ALL of the dampers so that the entire set of felt blocks move away from the strings at the same time. Gravity and springs reset the dampers to the rest position.

“In spite of the importance of the pedal and its right use . . . there is no branch of piano technique so little understood or so much neglected by both teacher and pupil” ~ Chopin

I hope that this blog serves as a little technical understanding of the pedal and will aid in the pedagogy and performance of the piano. Perhaps we’ll fulfill Chopin’s desire to make it less neglected.

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