The Underside of a Piano, photo Steinway

The Underside of a Piano


Let’s take a look at the construction of the bottom of a Steinway & Sons grand piano and how it helps you get a clear, clean sound.

The parts making up the underside of a piano

From professional musicians to preschool children, everyone can identify the most prominent parts that make up the piano, including the keys, the lid, and the pedals. More than 12,000 parts make up a Steinway grand piano, with the parts composing the underside of a piano being a mystery concealed from most.

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Looking at the underside of a Steinway grand piano, you can see three metal bracing bars, past which the wooden soundboard is visible. The bracing bars are used to hold the large, curved rim of the piano in shape. These are connected to the cast-iron frame with bolts. The bracing bars, however, are not screwed into the piano’s rim. Instead, they are glued and dowelled in order to ensure there is no metal contact within the construction of the piano. The only other piece of metal present holds the three bracing bars together. This helps keep the signature sound produced by Steinway pianos clean and pure.

How the underside of a piano is constructed

Steinway pianos are renowned for their unrivalled quality. This is achieved through the painstaking work of Steinay’s expert craftspeople; a Steinway grand piano takes a year to complete. All Steinway pianos are handcrafted using the highest quality materials available, using techniques favoured by Steinway & Sons for over 100 years. Many parts of the process of producing our pianos have been unchanged for generations.

The bridge is glued to the top of the piano’s soundboard and produced from laminated maple. Vibrational energy is transferred from the strings to the soundboard via the bridge.

In 1936, Steinway & Sons developed the innovative and groundbreaking diaphragmatic soundboard, which allows a piano to vibrate more freely, creating a warmer, richer and more resonant sound for a longer period of time. The grand piano’s soundboard and bridge are joined along with the iron plate inside the piano rim. Placing the soundboard and bridge at the correct heights is a precise process that calls for a keen eye and an accurate hand. The iron plate is cast in one piece from bell-quality iron, produced in our own foundry using Steinway’s unique castings.

The Underside of a Piano - photo by Steinway & Sons

Steinway’s superior sound quality

It is this painstaking process and dedication to quality that enables a Steinway piano to develop its own unique musical personality. Steinway & Sons are committed to going above and beyond to produce the most outstanding quality instruments available worldwide. With patented designs and materials sourced from the most specific regions to meet our exacting standards, Steinway pianos are sought after by master pianists, budding musicians and collectors.

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What is a piano soundboard made of?

Steinway pianos are made from Sitka Spruce. This wood is sourced entirely from one island in Alaska due to the high standards held by Steinway & Sons. This location’s unique micro-climate affords the wood with a superior grain density, direction and colour; this improves the transmission of tonal string vibrations.

What makes the sound played by a piano cleaner?

There are many reasons why your piano may not produce the level of sound quality you expect from it. While Steinway pianos produce superior sound, if they are not cared for properly or tuned regularly, this may deteriorate over time. For support on adjusting the pitch, cleaning, regulation and voicing and the completion of minor technical repairs, contact our Tuning Department.

How to remove the soundboard from an upright piano?

It is recommended that you only work with a specialist piano technician if you require your piano to be serviced or restored. Your Steinway piano is a fragile and prized possession, and attempting to complete a repair yourself could lead to irreparable damage to your Steinway.

Contact the Steinway Restoration Centre for more information.

What is the thing at the bottom of a piano called?

At the bottom of a piano, you will find the piano pedals, which control sound produced by the instrument. On the underside of a Steinway piano, you can see its metal bracing bars and wooden soundboard.

What is the wooden part of the piano under the frame called?

The wooden part of a piano, which is visible underneath the frame, is known as the soundboard. The soundboard can be considered the diaphragm of a piano, which amplifies the sound produced.