What is a grand piano’s action?

The piano’s action is the mechanism that causes the hammers to strike the strings after a key is pressed. Simply, it is what transforms the player’s touch into sound and runs along the width of the piano, behind the keys.

As with many of the 12,000 plus parts that make up a Steinway grand piano, a Steinway’s action is a unique force of innovation, made up of thousands of parts on its own, including the hammers, capstan and key lever. Upright pianos also feature an intricate action.

What is known as the double escapement action or repetition action was an early Steinway innovation. This made it possible to play a note again before the key had returned to its original position after being pushed down by the performer. This is achieved using a spring; the hammer rests on a piece of leather called the check, and while the key slowly releases, a spring on the repetition leaver takes over, holding the hammer so the note can be played again. This helps pianists repeat notes at a much faster pace than on pianos without this type of action.

A feat of engineering, the addition of a tubular brass rail with a Bubinga hardwood insert, which is particularly strong and stable, ensures the parts of the action stay exactly where they are intended to be. This reduction in variation makes the touch of the piano much more positive. As the rails and the corresponding action part are held under tension, there is very little energy loss while the piano is being played, which contributes to the clarity of the sound produced by the instrument.

How a piano’s action is constructed

The construction of a piano’s action requires absolute preciseness. The action assembly is mounted onto a tubular, metallic action frame, and the hammers are cut from a tapered sheet of felt. A set of hammers is placed in a press, forcing the felt into shape before it is glued to hammer mouldings. The hammers are glued to the hammer shanks before the action assembly and the keyframe are carefully put together and placed into the instrument. Precise placement is necessary to ensure that the hammers strike the strings at just the right place.

The action is then broken in and put through multiple checks to ensure it meets Steinway’s standards for tonal perfection. Today, Steinway also uses a computer-monitored measuring machine to check the exactness of the action parts. By taking multi-dimensional photographs, craftspeople can guarantee each part that makes up your Steinway meets our rigorous and exact specifications.

How the latest Steinway action sets Steinway pianos apart

Steinway is known for its historical patents and continues to adapt and improve its manufacturing methods and designs decade after decade. This results in pianos that will stand the test of time and that offer musicians unrivalled levels of quality in terms of materials and playability. Time after time, Steinway’s leaders have proven the impossible to be achievable with time and dedication.

This dedication to continuous innovation is what makes Steinway pianos different. The Steinway action offers unparalleled control and responsiveness, opening the door to more exciting and inspiring musical experiences.