What are pedals for?

Most modern pianos are equipped with three pedals. But what exactly do they do? And have they always been there? To understand that, we need to step back in time…

Before Pedals: Levers, Slides, and Other Tricks

Before the invention of the piano, keyboard instruments like the harpsichord had no pedals. Yet, makers were already looking for ways to vary the instrument’s tone color. They used hand-operated levers or sliding stops (not while playing). For example, a harpsichord might include a lute stop that imitated the short, plucked sound of the lute, or a nasal stop that gave a more piercing timbre.

But these changes only affected the tone color — not the volume — and could only be engaged between pieces. No mechanism yet existed to shape musical expression while playing.

The Arrival of the Pianoforte

Around 1700, the pianoforte changed everything. For the first time, the same note could be played louder or softer, simply by varying the pressure on the key. A true revolution.

However, the idea of a foot-operated control would take a little longer to appear.

The First Knee Levers

By the mid-18th century, thanks in part to German maker Gottfried Silbermann, the first knee levers appeared: small mechanisms under the keyboard, operated by pushing upward with the knees.

One lever lifted all the dampers to prolong resonance (the ancestor of today’s damper pedal), the other softened the tone (similar to today’s soft pedal).

Inventive makers soon added more knee levers or hand stops, sometimes imitating the tone of other instruments (harp, bassoon…), or even adding drums and cymbals for theatrical effect. Early “showpiece” keyboards, you might say.

Foot Pedals: A Key Breakthrough

In 1783, famous English maker John Broadwood replaced the right knee lever with a foot pedal. This greatly improved playing precision and control. It was the birth of the modern damper pedal (often called “sustain pedal”).

By the end of the century, pedals multiplied. A 1794 Érard model boasted six: forte, una corda, harp, bassoon, celesta, and Janissary (percussion).

Some were more gimmick than necessity, but experimentation was in full swing.

An Érard model from 1794 featured six pedals!

1808: The Invention of the Una Corda Pedal

Another milestone came from Sébastien Érard, who in 1808 designed the una corda pedal. This ingenious system shifts the entire action slightly to the right, so the hammers strike only one string (in practice, usually two) instead of three. The sound becomes softer, more veiled, less dense.

These two pedals — the damper pedal (sustain) and the una corda pedal (soft) — became standard. Knee levers, being awkward, gradually disappeared.

The Arrival of the Sostenuto Pedal

In 1844, French maker Jean-Louis Boisselot patented a third pedal: the sostenuto pedal. Placed in the center, it sustains only the notes already pressed when the pedal is engaged. This lets bass notes resonate while playing staccato above them.It’s clever, but not very easy to master, and is still rarely used in everyday playing.

Steinway quickly adopted it, and it eventually became standard — but only on grand pianos.

(Note: The damper pedal is often called the “sustain” pedal. This is common and understood, but don’t confuse it with the “sostenuto” pedal — they serve different purposes.)

Pedals on Upright Pianos

Upright pianos, which became popular later, immediately adopted the two main pedals.

The soft pedal works differently here: in an upright, you can’t shift the whole action sideways as in a grand. Instead, a simple lever moves the hammers closer to the strings by a few millimeters. With less travel, the hammers strike with less force, naturally reducing volume. It’s not exactly a true una corda effect, but it comes close.

The sostenuto pedal is rarely found on uprights (except on very high-end models).

For a long time, uprights had only two pedals. But since they are often apartment instruments where lower volume is desirable, a third pedal often appeared in the center: the practice mute.

The practice mute: a strip of felt placed between the hammers and strings.

This is a simple strip of felt lowered between hammers and strings, allowing very quiet practice — perfect for apartments. It’s usually operated by the middle pedal, in the same place the sostenuto pedal sits on a grand. But not always: on some models, the mute is operated by a hand lever, or even by systems reminiscent of… the knee levers of old pianofortes!

On a few uprights, some makers have tried to approximate the sostenuto effect. They designed a middle pedal that works like a damper pedal but only for the bass notes. This allows left-hand chords to sustain while the right hand plays staccato. It’s a clever idea, but rarely used in practice.

In Short

Among all the experiments, two pedals became essential:

– On the right: the damper pedal, which sustains the sound.

– On the left: the soft pedal, which reduces it.

In the middle, you’ll often find a third pedal:

• Sostenuto pedal — almost exclusively on grand pianos.

• Practice mute — only on upright pianos.

👉 Need Advice or Regulations?

Not sure if your piano’s pedals are working correctly?

Feel free to contact me — I’ll be happy to explain and adjust them for you.