Piano pedals serve as mechanical helpers to achieve expressiveness in your playing that would be difficult or impossible to do with your hands alone on the keyboard. Most pianos have two or three pedals, each with its own unique function. Pedals are connected to the action of the piano through mechanical linkages and metal rods in acoustic pianos, or via electronic switches in digital pianos. The entire pedal mechanism consisting of the pedals, the linkage rods and springs, and the bracing that holds everything together is the “trapwork.” The three pedals arranged left to right are: the soft pedal, the sostenuto pedal, and the sustain (or damper) pedal. In pianos with only two pedals, the middle sostenuto pedal is omitted.

FIGURE 9-6: Piano pedal trapwork

The Soft Pedal

The leftmost pedal allows the player to lower the volume of the piano slightly. Use the soft pedal for very soft passages where even the lightest touch on the keyboard produces too much sound. The term una corda (Italian for “one string”) instructs the pianist to use the soft pedal. (Usually there are three strings per note struck by the hammers in a grand piano action. When the soft pedal is depressed, the entire keyboard action shifts to the right so that the hammers now only strike one or two strings.) Upright pianos and electronic pianos use different methods to soften the sound, but the direction una corda applies to them as well. Use the soft pedal when you want to accomplish the softest possible sound on the piano. The effect is subtle but it will give you some extra softness when you are already playing as softly as you can.

The Sustain (or Damper) Pedal

The rightmost pedal is called the sustain pedal or alternately the damper pedal. This is the most often used pedal in piano playing, so much so that it is often referred to as just “the pedal” without further specifying sustain or damper. Where the soft pedal has a very subtle effect on the sound, the sustain pedal creates a very dramatic change in the music. Normally when a key is released, the sounding note stops immediately by means of a felt pad called a damper that presses against the vibrating strings. When the sustain pedal is depressed, all of the dampers in the piano are lifted out of the way, and are effectively disabled. Without the dampers to stop the strings from vibrating, every note you play on the piano will sound indefinitely—even after you have let go of the key.

This continuously sustained playing can create a wonderful effect as the notes overlap each other's sound for as long as you hold down the sustain pedal, or until the strings stops vibrating on their own. Unfortunately, this overlapping of sounds can also create a terrible clamor if the notes played are dissonant intervals or too close together. Because of the potential to greatly enhance the music or just create noise, the sustain pedal should be used judiciously.

Usually the sustain pedal is depressed for passages of a single harmony or chord. After playing a different harmony chord, the pedal is released and redepressed. When you release and redepress the pedal it is called changing the pedal. The marking to depress the pedal is simply the abbreviation Ped. and the symbol to change the pedal is a ?. Releasing the pedal without redepressing it is indicated by a _| or a large asterisk*. More often than not there are no markings at all, and it is up to the performer to determine when to use the pedal.

Listen to the example notated in Figure 9-7, first with no pedal at all and then with the sustain pedal applied and hear how the sound changes. You can play this selection in C position, but for a change of pace, move everything up one octave so your left hand pinky is on middle C. The shorthand notation for playing everything an octave higher is 8va.

FIGURE 9-7: Sustain pedal demonstration

The Sostenuto Pedal

The middle pedal on a piano is a very specialized mechanism, and it is not present on every piano. It acts as a selective sustain pedal. Unlike the normal sustain pedal where all eighty-eight keys will sustain when the pedal is down, the sostenuto pedal will only sustain the notes you are actually playing at the moment the sostenuto pedal is depressed. This allows you to sustain specific notes, and then play additional notes without the sustain effect while the original notes are still sounding. Use of the sostenuto pedal is an advanced application and exists mostly in Impressionist and modern twentieth century piano works. It is also used when a pedal tone is required (where you wish to sustain a bass note for a long period) while your two hands play in a nonsustained way. Listen to the example on the accompanying CD of the selective nature of the sostenuto pedal and its ability to add another dimension of expressiveness to the music. It would be impossible to create this passage without the sostenuto pedal.