The most common question one hears about the piano pedals is: ‘what do they do?” The three pedals at the foot of the pedal lyre are a constant source of questions and discussions and in this article, we are going to satisfy your curiosity once and for all.
Of the three pedals on the piano by far the most widely known function of that of the right pedal, or sustain pedal, as it is most commonly used by all who play the piano. As with all things genius the concept of what sustain pedal does is simple yet of paramount importance in the function of a modern piano- it sustains sound by lifting all the dampers and keeping them lifted for the duration of the pedal hold. Once you let it go, the dampers descend back on the strings, bringing all vibration to an end. Simple, right? The genius of sustain pedal is that it allows the sound to continue and overlap, giving the pianist endless opportunities to shade the sound and create a wide variety of special effects. Without the sustain pedal, or as it is sometimes referred to as a ‘damper pedal’, the sound of any given note would stop the moment the finger releases the key, resulting in dry, detached articulation similar to those of harpsichord or early pianoforte, thus eliminating the main feature of the modern piano – the cantabile sound (song-like, sustained tone).
The science of the sustain pedal
If you like to get really nerdy about it, the science of sustaining the sound goes beyond just merely lengthening it and allowing multiple notes to overlap. When all dampers are lifted off the strings, they allow each string to micro-vibrate. These sympathetic vibrations activate the inaudible overtones of all 88 keys (more on the overtone series here), thus infusing the sound with color, timbre, and richness. It is that inaudible micro-vibration, once it interacts with the soundboard, that is responsible for some of the unearthly beauty of some great piano playing.
Another element that is truly a deciding factor in how beautifully this sound manipulation works is the pedaling technique of the pianist. To truly master pedaling it takes years of consistent practice with attention paid to synchronizing the micro-movements of your foot with the movements of your fingers on the keyboard. This is a feat, of course, but is a learned skill, much like any other physical exercise. The more you do it, the better you will become at using the sustain pedal on a piano.
The high-caliber professional pianists often use the term ‘half-pedal’ and even ‘quarter-pedal’, as it indeed makes a difference as to how deeply you depress the pedal. Logically, the distance that dampers travel up from the surface of the string, allowing the string to commence and sustain vibrations, directly corresponds to how far your foot travels downward, depressing the pedal. Controlling this distance IS the art of pedaling. (the closer the damper is to the string the more obstructed the vibration, thus thinning out the ‘sustaining’ effect and shortening the elongation of the duration of the string)
To further complicate matters, there is the onset and the release of the pedal. The velocity and kinetic energy of how you ‘touch’ the sostenuto pedal with your foot determines the quality of sound you will get from using it. And, of course, the release of the sostenuto pedal, which determined the extinguishing of the sound, plays a key role in the final result. One often hears with the beginner piano students the ‘stomping’ on the pedal, which is where the foot lands on the pedal from too high in the air, and the soles of the shoes create noise on impact. This, naturally, is very disruptive to piano playing in general and results in a very basic sustain pedal utilization. Inevitably such an on-set of the pedal does not allow velocity control and usually, the foot goes all the way down fast, like a ‘gas’ pedal on a car. Likewise, the brisk release of the pedal can at times produce a noise of the pedal springing back into its stationary place, cutting the sound off. When performed perfectly, the release of the sostenuto pedal can create elegant tapering out of the sound, allowing it to softly waft off into the nothingness or to the next sound.
The middle pedal - Sostenuto pedal
Moving right along to the left of the pedal lyre, you might see what is known as a middle pedal, which is, to use a proper term is sostenuto pedal. It functions differently on grand pianos versus upright pianos, however, some high-end uprights will have the same sostenuto function available on the middle pedal.
The main function of the middle pedal is to sustain the keys (often bass notes) that have been depressed and HELD by the fingers before applying the sostenuto pedal. When done correctly, the one or more notes, having been ‘locked’ with their dampers raised off the string will continue to sound while all the rest of the keyboard will function normally, with no sustaining of other notes at all. This allows a ‘dry’ playing to occur over the sustained ones. Typically the left hand gets the most use of the sostenuto pedal as it makes musical sense for the lower bass notes to continue “grounding” whatever else might be taking place in the higher register. Additionally, the left hand can play something else on top of the notes that had been ‘locked’ by the sostenuto pedal, creating a richer texture, and adding to the almost superhuman effect of having 3 hands.
This ingenious invention has truly a magnificent way of manipulating the piano’s sound and using the acoustic capabilities of a well-built grand piano. The fun begins with the fact that while you are holding the sostenuto pedal down you can also use the sustain pedal as well. This gives your ‘dry’ layer an option of not at all being ‘dry’, its own independent color palette, and capacity for sound effects. Once you release the sustain pedal (the right pedal) over the sostenuto pedal (middle pedal) you will hear the continued ‘humming’ sound of the residual vibrations, no matter how long the locked notes were being held. Each note played above the ‘locked’ ones will re-ignite string vibrations generating soft overtones belonging to those pitches. The soundboard reflects the sound waves back with each additional pitch that is played anywhere on the keyboard. When performed well this effect is truly magnificent – it almost gives a piano an organ-like sound – imbuing the sostenuto pedal with the function of turning the piano from a percussion instrument into an organ pipe, albeit very quiet.
There isn’t a great deal of repertory dedicated to the sostenuto pedal, though more and more new music utilizes this feature. The middle pedal can be certainly taken advantage of in the performance of standard repertory, albeit wisely.
The middle pedal, being a highly calibrated technological advancement works best in grand pianos. While some very exclusive, premium upright pianos replicate that function it doesn’t have the same power as it does on the grand, largely due to the physical constraints of the upright being a vertical piano, versus the grand piano’s strings being positioned horizontally.
One does however find a middle pedal on the upright piano quite often. What is it and why is it there? It is a practice pedal, designed with the sole purpose of muting the entire keyboard for a quiet, neighbor-loving practice session. You can tell that the middle pedal has a practice pedal function if there is an indentation to the left of it, where the pedal can be slid into to lock itself in the depressed position. Once you put the practice pedal ‘on’, the layer of cloth is placed between the hammers striking the strings of the piano, thus making the sound substantially softer, less colorful, and thinner. This is a very useful feature for educational environments. Needless to say, in apartments with thin walls, this is very helpful so as not to disturb the neighbors.
Una Corda, or soft pedal
The third and last pedal on the left of the pedal lyre is the una corda pedal or soft pedal. It does exactly what its name suggests – makes the totality of the piano sound softer. The soft pedal shifts the keyboard to the right just enough to allow the hammer to strike one string instead of the three. If you look inside of your grand piano you will notice that about one-third up from the bottom (left side) of your keyboard the copper-toned, thicker brass strings are replaced by the thin, needle-like steel strings. If you look closer still, you will notice that there are three strings per hammer. This is what makes the sound of the modern piano beautiful with tone colors, texture, and depth. It also contributes to a powerful projection of the sound and uniform volume across all 88 keys. When the soft pedal shifts the keyboard to the right, the hammer only strikes one string out of the three, thereby reducing the volume, color, and depth of the sound. Hence the Italian name of the pedal – una corda, which means one string.
Just as with the sustain pedal (or damper pedal) the final result of using it depends on the technique of the pianist. Una corda pedal can be used in gradations of one-fourths of the full range of motion, shifting the keyboard just an iota, ever so slightly changing the kinetic synergy of hammers and the strings. The release of the una corda pedal, likewise, has an immediate effect on the sound, allowing it to bloom with colors, infusing it with full tone. Anecdotally, when asked what was the secret to his signature ‘cantabile’ sound, Arthur Rubinstein answered “I put down the soft pedal and play forte”. Naturally, there was a bit more to his touch than just that, but this statement holds true to some extent: it changes the quality of sound, creating a softer, less-edgy initiation and release of sound.
At the end of the day, everything rides on the quality of the acoustic piano at hand.
All these elements have an almost equal role in the facilitation of a good sound: the felt between the hammers, the quality of the material of hammers and strings themselves, and the piano pedals’ design and regulation. The left pedal, for instance, can move too far to the right if not regulated properly, accidentally hitting a neighbor string, which creates a pitch cluster that sounds like a wrong note. The damper pedal needs to go high enough to completely liberate the strings. This too requires a good regulation to ensure the range of motion is enough for skillful usage, where ‘quarter and half-pedal can be achieved with dampers lifted closer to the strings. The piece of felt that comes into contact with the string has to be in perfect condition and of high quality to properly mute the vibrations and end the sound. Natural wear and tear as well as the initial cost of the piano play a significant role in the entire pedal system.
The type of piano you have will ultimately determine the pedaling experience: grand vs. upright. If selecting or playing upright piano – pay attention to the pedals and if there are three, check if the middle pedal sustains the bass notes (sostenuto pedal function) or is a practice pedal (the mute mechanism). On larger grand pianos all pedaling functions have more audible variation than on the smallest baby grand pianos or upright pianos, due to the length of the strings and acoustic chamber.
In a growing segment of quality digital pianos all of these effects are reproduced without any of the moving parts: no longer does one depend on thousands of little pieces of wood, felt and metal to work in perfect accord and respond to the pianist. The algorithm makes all the necessary adjustments once you touch the pedals on a digital piano. The effect cannot be fairly compared to the acoustic pianos since the result is pre-programmed and overall is less sensitive to the individual performer. That being said, the high-end digital pianos (such as the Yamaha Arius series, Roland FP 90X, Suzuki VG-88, or Kurzweil Home KAG100) have excellent pedal functions, essentially indistinguishable from their acoustic counterparts. Most have no use for the practice pedal as one can control the volume separately by a nob or a menu setting, so the middle pedal replicates the sostenuto pedal function.
As with all high-end mechanical/digital products – you get what you pay for. The premium luxury piano brands such as Fazioli, Steinway, Bluthner, Bosendorfer, Bechstein, Yamaha, and Kawai have superbly constructed pedals that perform their functions 100 percent. The cheaper the piano the less responsive the entire pedaling system is. The same can be said of digital pianos as well. Keep in mind that maintenance is a huge factor, however.
We hope this answered all your pedal questions