The Anatomy Of An Upright Piano

The Anatomy Of An Upright Piano

The inner workings of a piano is often a mystery, even to some pianists! With thousands of parts working in complete harmony to create an intended tone, it’s often not surprising that many don’t take the time to understand their instrument.

Today we thought we’d take a moment to help explain a little more about some of the more basic intricacies of what goes into a piano, what they do and how they work together to create an instrument that will be loved for years to come.

The Front & Sides


Firstly, we’ll start with the outer shell of the piano, this is known as the cabinet and determines what the piano essentially looks like, how large it is, what finish it is in and any external features such as fittings, casters, soft fall lids.

Despite this, there is an fully lot that goes into the cabinet of an upright piano.

Top Board:

A piano top board

The top board of the piano, also commonly known as the piano lid, is the highest point of the piano and often opens on a hinge. This is important as not only is it the easiest access point to the inside of the piano, but it also allows for further sound projection. Many pianists enjoy playing with the top lid open because it helps offer the sound another direction to escape from and fill the room.

Fall Board:

Also sometimes commonly known as the lid for the keys, the fall board is the hardwood covering that ‘opens’ or ‘closes’ the piano. This cover is designed to not only aesthetically fit in with the piano design, but can often also house things such as music desks to help balance your devices or sheet music on.

Fall boards often get a bad reputation as if you drop them on your us, they hurt! This is especially important for younger children who may be playing or exploring the piano, so is definitely something to look out for!

Thankfully though, many brands, such as some in the Ritmüller range offer a more intricate ‘soft close’ fall board which instead of slamming shut, gently lowers to meet the keys.

The Keys

Set of piano keys

Where the magic happens! The keys on a piano are relatively self explanatory, however are the interface which allows the instrument to function properly. They sit in what is known as the key block, or key bed. Pianos classically have around 88 keys, there are those with more and some with less, however 88 is regarded as the standard. Of those 88, 36 are black and 52 are white to cover around 8 octaves.

The keys allow for not only the touch of the piano, but also the expression it allows for. Many people think piano keys are just as long as they look from the exterior (around 6 inches), however on many upright instruments, it’s not uncommon to see keys that are around 15-16’’.

The reason for this is because a longer key length allows for a wider pivot point on the piano, allowing for more expression and sensitivity in play.

The Side Board / Side Arm

The side profile of an upright piano

The side board is essentially the ‘side’ of the piano. Much like the top board and fall board, they help determine the style and shape of the piano. For example many piano manufacturers will take a lot of pride in their sideboards, but including elegant swooping curves to give a more premium look.


Not all pianos come with legs and for the most part, this is a purely cosmetic decision. Traditionally, legs on pianos were designed to offer more stability and steadiness when moving on the casters (wheels). However as most pianos that are found at home don’t generally move much, many have chosen to opt for a more modern design and remove the legs and casters, instead opting for sliders.

Casters / Sliders

As just mentioned, the casters of the piano are essentially how it moves. casters are small wheels that have been specially designed to support the weight of the piano and evenly distribute it. Whilst generally incredibly sturdy, it is possible for casters to collapse under the weight of the piano. This is a job that a piano technician will need to fix as these instruments are incredibly heavy and difficult to move correctly.

One common misconception about casters however is that they are intended to ‘move’ the piano over long distances. They’re not. Instead, they should be used more as tools to allow you to pivot your piano in small increments.

Other pianos, particularly those that do not have legs, often come with a slider mechanism underneath the piano to allow for a similar effect on hard surfaces. However as you can expect, these are far more difficult to move than those on castors and generally only work on smooth surfaces such as wood.

Lower And Upper Front Board

The front boards help not only determine the finish of the piano, just also cover the inner workings to give a sleek and elegant finish to the instrument. With a little know how however, they can be relatively easily removed to expose the inside of the instrument and the actions. As there are so many exposed components on show when a front board is removed, we wouldn’t recommend this and would instead only remove the cover of your piano when a technician is tuning it.

The Pedals

We’ve actually already written an in depth guide to the pedals on pianos, and how they often differ between brands. Some pianos may have two pedals, or even just one, however most commonly many have three. We will briefly mention what they most commonly do here on many three pedalled pianos.

The left pedal is most commonly known as the soft pedal. When this pedal is pressed, all of the hammers inside the piano are moved closer to the strings. Because of the reduction in distance, when the hammers strike the strings, the sound volume is reduced, so is ideal for those wishing to still play, but are conscious of those around them.

In the middle, you will commonly find either a Muffler or Sostenuto Pedal. A muffler pedal is also known as a practice pedal and essentially drops a piece of felt between the hammers and strings, greatly reducing or even sometimes muting the sound. The other use for the middle pedal on some models is known as a sostenuto pedal, which helps keep the dampers raised away from the strings of any keys played just before depressing the pedal, allowing for sustain across selected notes.

The right pedal is the most commonly used and one that we recommend many players explore the most. This is the sustain pedal, also known as the damper pedal. This pedal keeps the dampers lifted on the piano, even if the fingers are taken off of the keys, sustaining all played notes.

The Back

The back of an upright piano has far less features that the front, however is essentially what creates the instrument’s sound.

The Soundboard

The soundboard of a piano

Essentially, the ‘amplifier’ of the piano. If you’ve ever wondered why pianos can be plated so loudly, it’s because of the soundboard. Soundboards are actually an extremely delicate part of the piano as the wood essentially has to be flexible enough to allow for vibration to travel through it, but not stiff or soft enough to either made the sound collapse or be too rigid so the wood doesn’t vibrate correctly. For this reason, most soundboards are made from spruce due to it’s versatility and resonance. To learn more about wood types on pianos, read our guide here. The soundboard is also visible on the inside of the piano.

Attached to the soundboard is also a structure designed to help keep it sturdy and help ensure the soundboard doesn’t snap or crack. This is the soundboard ribs.

The Back Posts

the back posts of an upright piano

Also helping add to the structural stability of the piano is the back posts, which are designed to take the tension and weight of the piano away from the soundboard and into a hard wearing wood. Back posts do different things on different pianos. In some pianos they are structural. That is, they help support some of the string tension. In others they are used to stabilise and dampen the plate via strategically placed nose bolts. In still other designs they are simply decorative.

Inside The Piano

Much like many people don’t understand the fine tunings of how a car engine works, the same too can be said about the inner workings of a piano, with so many bolts, parts, connectors and materials working together, it can be incredibly complex to explain. Here we’ll offer insight into the most common parts of the instrument and the ones that may affect your playing. To learn more about how the piano physically makes its sound, read our guide here!

The Action

Arguably the most complicated part of the instrument, the action on a piano is made up of many different parts working together to create the exact force that the player hits the key at. Due to being transposed vertically, upright piano actions are actually more complex than those found on grand pianos.


The bass strings of an upright piano

Piano strings are some of the hardiest and also most carefully selected strings in the musical world. Piano strings are almost always made from the same materials; high carbon steel, and copper. Both of these are incredibly long lasting, hard wearing materials that can keep up with the tension of the piano and most importantly, won’t snap easily.

The treble and middle of the piano uses three carbon steel strings per note, and the bass uses a carbon steel core with a copper winding. They are wound in the same way as a guitar string, in that they have a solid core, with an outer winding around the string, although on a piano, they are much longer, much thicker (especially in the lower end) and capable of a far higher tension.

The treble strings on an upright piano

Piano strings are unbelievably strong. In fact, each string on a piano is tightened to between around 75kg and 100kg of tension, so one string on a piano has more tension than a whole guitar. All of this combined means the total tension of all the strings in a piano is around 20 tonnes. Fun fact: That’s about the same weight as a fully loaded bus, or three African elephants! Learn more about how piano strings affect your instrument here!

Tuning Pins

Piano tuning pegs

At the end of the strings are the tuning pins. There are what technicians and tuners will use to adjust the tension in the string to allow them to resonate at the correct frequencies. Unlike other instruments, piano tuning is interesting because it doesn’t just rely on the single string, because of the sheet level of tension, the string must also resonate with those around it so it is a far more complex job than tuning something like a guitar. To learn more about the tuning process, read our guide here.

The Hammers

The hammers are the driving force behind every piano, they are what strike the string and cause it to vibrate. The wood type of the hammer is also a crucial component of the piano and many are made from durable, hardwoods that still hold consistent resonating qualities. The best hammers in the world are made from walnut or mahogany.

In order to add versatility to your sound, instead of being just wooden, piano hammers are covered with an incredibly delicately made felt. This is what helps allow the piano to whisper and sound felty whilst soft playing during pianissimo and become strident and powerful when played with some force during fortissimo sections.

Hammer Rail

The hammer rail on a c.bechstein upright piano

As mentioned in the pedal section, the Hammer rail is a padded strip of wood in a piano action that supports the hammers when at rest and in an upright piano is what moves forward when the soft pedal is pressed to shorten the distance between the hammer and the string, muting the piano slightly as the hammers are unable to travel as far.

Bridle Tapes

More one for the technicians, but something that we often hear customers ask what they are, the purpose of the bridle straps are to make removing and reinstalling the piano action easier during technical work. The straps keep the action from hanging down loosely which can cause them to catch on the key capstans and break when the action is put back in the piano.

Treble & Bass Bridge

The treble bridge of the piano, also known as the ‘long bridge’ essentially helps transmit the sound between the strings and the soundboard. It transfers the energy of the vibrating string into the soundboard for the top sixty-one keys of the piano. By exquisite craft and size, the soundboard then amplifies this tone to enrich the characteristics of the string sound, which creates the air movement to bring music to our ears!

The bass bridge does the exact same thing, however it bridges the energy of the vibrating string into the soundboard for the lower twenty-seven keys of the piano.

So there you have it! Just an incredibly brief insight into the levels of detail and composition that goes into a piano. To learn more about any of our instruments, or to visit our showrooms, contact our piano experts today!

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