Form and Function of A Grand Piano

Explore the Grand Piano

The grand piano is made of three major components. The picture on the right highlighted each major part of the piano.

1. The Case, which is the wooden housing of the piano.
2. The Strung Back, which is made of the back frame, soundboard, cast-iron frame, and strings.
3. The Playing Mechanism, which is the complex system of levers that transmits the actions of the pianist to the hammers that strike the strings.

The modern grand piano must fulfill two roles, that of a musical instrument as well as a piece of furniture. As a musical instrument, the piano must be designed in a way that allows for the best possible acoustics. As a piece of furniture, the piano must have an attractive outer appearance. Over the years, piano designers and manufacturers have strived to achieve a balance between the proper acoustical functionality and a visually appealing form.

Grand Piano Case

Explore the Case

The above picture of the grand piano which highlighted different components of the case.

The Wooden Housing of the Piano
The case is the wooden cabinet that houses the strung back and playing mechanism of the piano. The case must balance both proper acoustics and attractive looks. The purpose of the case is primarily decorative, but the wood also plays an important part in the resonant characteristics of the instrument.

Different Sizes
Grand pianos are produced in a variety of sizes. The case of a modern grand can vary in length from five feet two inches to nine feet ten inches, but different sizes, both smaller and larger, can be special ordered direct from the manufacturer. The different sizes of the grand piano are given their own individual names. The largest pianos (nine feet and larger) are referred to as “concert grands” and are normally found in performance areas. The “living-room grand” or “parlor grand” is about six to seven feet long and can be found in smaller performance venues as well as private rooms that have adequate space. The “baby grand” is about five to six feet long, and is usually found in private homes, teacher studios, and practice studios. The sound of a nine foot grand is generally of better quality than a smaller piano, due to its larger soundboard and longer strings.

Grand Piano Rim

Spine, Bentside & Tail

The rim is made of three distinct parts: the spine, the tail, and the bentside.

• Spine : The long straight portion of the rim that is on the left (bass) side of the piano
• Bentside : The curved portion of the rim that is on the right (treble) side of the piano. This distinctive shape is a result of the treble strings being shorter than the bass strings.
• Tail : The portion of the rim that is opposite the keyboard. On modern grand pianos, the tail is curved to match the bentside. Tails on harpsichords and many early pianos were usually straight across.

Construction of the Rim
The shape of the rim is derived directly from the wing-shaped harpsichord. Cristofori used the case of a harpsichord to build his first pianos, and the shape has now become the identifying feature of the grand piano. The rim is made of many thin sheets of wood, called veneers, which are glued, or laminated, together (similar to plywood). If the rim were made of one solid piece of wood, the wood could expand and contract across the grain due to changes in the humidity levels. Over time, this movement of the wood could result in the warping or cracking of the rim. By laminating many thin pieces of wood together and alternating the direction of the grain in each layer, the chance of this harmful expansion and contraction is virtually eliminated. The top (or outside) veneer is usually made of mahogany, and is finished to match the whole piano case. In order to create the distinctive shape of the piano, the long laminated rim slab is put into an iron press, and formed into the proper shape. The rim is glued together, and held in place by clamps until it dries.

Grand Piano Lid

Protection and Reflection

The lid, also called the top, is the wooden cover that is hinged to the spine and folds down to protect the interior of the piano when it is not being played. The front half of the lid is folded down when the lid is closed, and folded back when it is raised. The raised lid also serves as a reflecting surface for the sound waves that radiate from the soundboard. The waves come off the soundboard and are then reflected out towards the audience. When the lid is raised, it is held open by a wooden stick called the lid prop. Most lid props have a smaller stick called a half-prop, which can be used to keep the lid partially raised.

Grand Piano Legs

Treble, Bass, & Point
Three legs support the piano:

• The bass leg is the leg on the bass (left) side of the keyboard
• The treble leg is the leg on the treble (right) side of the keyboard
• The point leg is the leg on the end opposite the keyboard

The treble and bass legs are attached to the bottom of the keybed, and the point leg is attached to a small platform that is found under the tail of the piano. The legs of the piano must be sturdy in order to support the full weight of the instrument – which can weigh over 1000 pounds. The legs are made of solid wood – usually a hardwood such as birch or maple.

The Ferrule & Caster
On many pianos, the wood at the bottom of each leg is slightly flared out. This wider portion of wood is called the ferrule. The wheels that may be attached to the bottom of each leg are called casters, and these allow the instrument to be moved with greater ease.

Grand Piano Music Desk

Support for the Music

The music desk is the part of the case that holds the printed music upright for the pianist to see. The bottom horizontal portion of the music desk which supports the bottom of the printed music is called the music shelf. The music desk is hinged and usually can be set at several different angles. When not using printed music, the desk can either be folded down, or completely removed from the piano and set aside. The music desk can be very plain or extremely ornate, depending on the design of the piano.

Grand Piano Cheek, Keyblock & Keyslip

The Cheek

There are two cheeks on the piano, one on each end of the keyboard. The cheeks are connected to the rim, one at the end of the spine on the bass side, and one at the end of the bentside on the treble side. The keyboard sits between the cheeks, and is held in position by the keyblocks.

The Keyblock
The keyblock, also called the cheekblock, is the removable block of wood found on each end of the keyboard. These blocks hold the keyboard in place and keep it from shifting. The keyblocks are stained to match the finish of the case.

The Keyslip
The keyslip is the long removable strip of wood that runs the full front width of the piano. The keyslip is found just under the keys, and is designed to cover the keyframe. The keyslip is also stained to match the finish of the case.

Grand Piano Keyboard Cover

Protection for the Keys
The keyboard cover, also known as the fallboard or keylid, is the part of the case that folds down to protect the keys when the piano is not in use. The keyboard cover folds down between the cheeks, and rests on the keyslip when closed. The nameboard is the part of the keyboard cover that displays the name of the piano’s manufacturer. The name is usually stenciled in gold and is visible when the keyboard cover is raised, but hidden from view when the cover is folded down.

Grand Piano Pedal Support Structure

The Lyre, Pedal Box, and Backstays

The pedal support structure is comprised of the pedals and the various posts and braces used to strengthen and reinforce the pedal system. This wood and metal support structure consists of the lyre, the pedal box, and the backstays.

The lyre is made of posts that are attached to the pedal box at the base. In the 1800’s many pianos had extremely ornate casework, and the lyre was usually designed to match the traditional Greek stringed instrument from which it takes its name. In modern times, the lyre has lost its identity with its namesake, and is usually made of two nondescript wooden posts. The pedal box, which may also be called the lyre box, is the wooden housing for the three pedals on the piano. The portion of the pedals that stick out of the pedal box are called the pedal feet, and the red felt that surrounds and pads each of the feet is called the pedal cushion. Two metal rods called backstays support and reinforce the pedal mechanism. The top of the backstays are bolted to the back frame of the piano, and the bottoms are secured to the pedal box. The pedal support structure can (and should) be completely removed from the piano when moving the instrument. This eliminates the chance of breaking the support structure when the piano is in transit.

Click here for more information on the function of each of the pedals.

Grand Piano Strung Back

Explore the Strung Back

Above picture of the Grand Piano that highlighted different components of the strung back.

The Source and Amplifier of the Sound
The parts of the strung back work together to produce and amplify the sound of the piano. The playing mechanism initiates the sound by setting in motion a chain of events that ends with the hammer striking the string. At this point, the strung back goes to work. The strings, which are held at an extremely high tension over the cast-iron frame (also called the plate), begin to vibrate when struck by the hammers. The strings by themselves, however, are not loud enough to be heard unless they are linked to the soundboard, which acts as an amplifier of the sound waves generated by the strings. The strings, cast-iron frame, and soundboard are supported by a system of internal braces, called the back frame.