The special case of the grand piano, called the rim, reveals the design legacy of STEINWAY & SONS behind the Boston. The rim contributes to the stability of the piano, offering support for the soundboard. The outer rim consists of several layers of mahogany, and the inner rim of the Boston grand is made of hard rock maple. This high-quality hardwood is pressed with horizontally oriented grains, providing more stability, and exceptional power and richness of sound.

The wide-tail design of Boston grands is a special STEINWAY & SONS innovation that creates more surface area in the soundboard. This enriches the sound, giving the pianist the impression of playing on a larger piano. Boston grands are wider at the tail than most pianos of the same length — allowing a larger soundboard area and producing a richer sound. The larger soundboard area also permits better placement of the bass bridge — which yields more volume, greater tone, and a bass that sings.

High-grade, straight-grained, quarter-sawn spruce is used for its resonant qualities and for its high strength-to-mass ratio. The soundboard is solid and not laminated, creating the best resonance and projection of sound In 1936, Steinway patented the diaphragmatic soundboard, designed to be thicker in the middle and gently tapered to the edges. The Boston soundboard has tapered thickness from bass to treble. A thinner soundboard in the bass area vibrates more freely. So you get a bigger, richer, fuller tone.

One of many proprietary STEINWAY & SONS innovations, the patented Octagrip™ pinblock can only be found in Boston pianos. The Octagrip™ pinblock is made of 11 layers of hard rock maple glued in different grain angles of 60 degrees. This quad-directional structure grips the tuning pins from eight directions, ensuring a tight fit, uniform pressure, and smoother tuning — affording greater stability under tension and enabling the piano to stay in tune longer.

Every single piece of the piano vibrates while being played —except the plate, which is dedicated to a single function: ensuring total stability. Thanks to STEINWAY & SONS’ design expertise, based on its long history of research and innovation, this cast iron plate can withstand the nearly 20 tons of string tension created by the 220-plus individual strings.

Each of the 88 keys of a grand or upright piano transmits its movement to a small, felt-covered wooden hammer which strikes one, two or three strings. In 1880, STEINWAY & SONS introduced pear-shaped hammers with reinforced shoulders and metal ligatures to ensure superior stability and a more powerful sound. This exclusive STEINWAY & SONS design is also a part of Boston grand and upright pianos. Boston’s STEINWAY-type action geometry yields faster reptition, better stability, and heightened responsiveness — allowing the musician to play with maximum expresssion and control.