At its core, a piano is an acoustic instrument where sound is created by felt hammers striking strings. The strings vibrate and transfer energy to the soundboard. The larger the piano, the longer the strings and the greater the soundboard area—which results in more powerful, richer, and more resonant sound.
Small vs Large Pianos: The Physics
Key Size and Control
Beyond string length and soundboard area, the physical size of the piano also influences the length of the keys themselves—specifically, the full key stick that extends back into the piano, not just the visible part. Larger pianos (7’+) typically feature longer key sticks. This increased length provides several advantages for the player:
Enhanced Control: A longer key stick acts as a longer lever, offering the pianist greater mechanical advantage and a more nuanced feel. This allows for finer control over the hammer's impact on the strings.
Improved Dynamic Range: The superior control afforded by longer keys directly translates to a wider dynamic range. It becomes easier to achieve very soft passages (pianissimo) with precision, as well as powerful fortes, due to the increased leverage and responsiveness.
Easier Soft Playing: The added control makes it significantly easier to play softly and evenly, as the slight variations in touch translate more effectively through the longer key mechanism.
While many assume upright and grand pianos differ only in form, the sound differences are significant. Upright pianos compress the action vertically, limiting the length of the strings and soundboard. Upright actions rely on springs to reset the hammer. Grand pianos offer horizontal string alignment, allowing better gravity-assisted action, richer tone, and increased dynamic range.
Tone: Influenced by string length, key length, hammer action, and voicing. Larger pianos offer more nuance.
Volume: Depends on how much energy the soundboard can project. Bigger instruments = more sound.
Resonance: Longer strings vibrate more deeply and sustain tones longer, creating lush harmonics.
Not always. A well-crafted upright like the Steinway Model K can outperform a poorly built grand. But within the same quality tier, size improves performance.
Larger pianos, especially from premium brands like Steinway & Sons, often tend to hold value due to their musical capabilities and desirability among advanced players and institutions.
Piano size shapes your sound experience. If you're exploring options, visit our showroom or connect with a piano consultant to compare in person.
Curious how different piano sizes sound in your space? Book an appointment or download our free Piano Buyer’s Guide.