The Three Piano Pedals: What Are They For?

Whether you play an acoustic or digital piano, in most cases, the stand or cabinet comes fitted with three pedals. If not, then you might be lucky enough to have the option to connect up a separate set. But what exactly do you do with these mysterious pedals? Bax Music product specialist, Marc will now illuminate everything!

The Three Pedals, From Right to Left

If you’re learning to play the piano, then your hands are already pretty full with the 88 black and white keys and don’t you probably haven’t had much head-space left to even think about the pedals until now. Ok, so you probably already know that the sustain pedal sits on the far right, but what about the other two? These are the ones we’re going to take a good look at in this blog. We’ll start off with the basics: by simply naming each of the three pedals. From right to left, you have sustain, sostenuto, and una corda. While I’ll be using the structure of an acoustic piano as a guide, the order of the pedals used with digital pianos will be the same, if we ignore the possible addition of one or more pedals with other, extra functions, like the Yamaha CVP, where the far left pedal is a pitch bender!

The Sustain Pedal

The sustain pedal, also known as the damper pedal, is one of the most-used pedals of a piano, as well as of synthesizers and keyboards. The term ‘damper’ is usually (and somewhat confusingly) used when referring to this pedal on an acoustic piano, since when the pedal is pushed, the internal ‘dampers’ that rest on the piano strings are lifted, allowing the strings to vibrate more freely – hence ‘sustain’. This is a mechanical function, while the sustain pedal of something like a synthesizer is a ‘parameter’. Sustain means persist, and that’s exactly what happens when the pedal is pressed. The sound of the chord or note that’s played persists, even when you lift your fingers from the keys, and will carry on until you lift your foot from the pedal, or (in the case of an acoustic piano) the strings cease to vibrate naturally. It takes a little practice to get the hang of the timing – when to push and release the pedal – but once you have it, you get a flowing transition between notes and chords. This also achieves a richer sound, because once the dampers are removed, as you strike notes, the other strings vibrate and add overtones, so you can use this pedal as a kind of reverb. Where you see the word ‘Ped’ when reading sheet music, this notation indicates when you need to push and release the sustain pedal. When playing an acoustic piano, you can also experiment with pushing the pedal down just a little. This ‘half-pedal’ technique is sometimes possible when playing more expensive digital pianos – and you can find out if a certain model has this function by checking the specifications.

The Three Piano Pedals: What Are They For?

The Sostenuto Pedal

The middle pedal is the sostenuto pedal. This is the one that tends to cause the most confusion because in terms of function, it’s actually a lot like the sustain pedal. Sostenuto stems from the Italian word, ‘sostenere’, which also means to ‘persist’. In music terminology, this is a word that can have more than one meaning, but in this case, it’s damping (you may also come across the term ‘adagio sostenuto’, but this indicates that a certain tempo needs to be maintained). In the case of the sostenuto pedal, only the notes that are struck at that moment are sustained until the pedal is released. But how is this pedal actually used? Well, you could play a chord with your left hand, then press the sostenuto pedal, leaving you with two free hands to play a more complicated part over the sustained chord. But this is different to the sustain pedal in that the notes played will not be sustained, while the chord you played first is. So, there is no ‘mess of notes’ as with the sustain pedal.

The Sostenuto Pedal of Upright Pianos

With upright pianos, the middle pedal will almost always have a different function. For example, it might have the function of a practice pedal, where the strings are tightly damped so that you don’t bother your housemates or neighbours with too much noise when practicing the same piece over and over. Some pianos will helpfully allow the pedal to be locked, so you don’t have to continuously hold it down. Anyway, it’s the case that most pianos don’t actually have a sostenuto pedal in the traditional sense, and as such, a lot of sheet music doesn’t even ask for it.

The Three Piano Pedals: What Are They For?

The Una Corda Pedal

On the far left sits the una corda pedal, or ‘soft pedal’. In Italian, ‘una corda’ literally means ‘one string’. To understand what this pedal does, we have to take a take a look at the inner workings of a piano: most of the notes of an acoustic piano are actually produced by a group of three strings, but have been tuned in a specific way so that, when struck, they sound like a single note. The grouping of the strings shapes a richer sound that’s full of overtones, which we call ‘unison’. So, when you press a single key of a piano, the hammer often actually strikes multiple strings. What the una corda pedal does is give you a more dampened sound that has less overtones to it (well, it still has some overtones, since every note is always made up of a root note and a range of overtones). When the una corda pedal of an acoustic grand is pressed, all the hammers are pushed to the right so that only one or two strings are played per note, or the ‘single string’ is struck with a different part of the hammer. The effect of the una corda pedal of grand pianos was actually much clearer and more audible centuries ago, and you were able to play with the subtle sound differences it could create when pushing the pedal less or more.

The Una Corda Pedal of Upright Pianos and Digital Pianos

With an ‘upright’, or standing piano, by pressing the pedal on the left, the hammers are brought closer to the strings, to more or less create a similar effect. The construction of the hammer mechanism inside a grand piano is able to create the full effect, simply because there is more room inside a grand piano to accommodate the shifting of all of the hammers, while an upright simply doesn’t have the room. The una corda pedal of a digital piano has the same effect of that of a grand piano, since it’s recreated digitally. And as mentioned previously, the left pedal of a digital piano can sometimes have an entirely different function, depending on the model.

Are there any other things about the piano that you’d like us to explain? Let us know in the comments!