A standard grand piano consists of more than 12,000 individual parts.

The modern grand piano is a feat of engineering perfected over 300 years since Bartolomeo Cristofori invented the first 'fortepiano' around 1700 in Italy. A standard Steinway Model D contains exactly 12,116 individual parts, with the 'action' alone accounting for nearly 8,000 of those components. This action is the mechanical system that connects the keys to the hammers, allowing the player to control volume and tone through velocity.The internal tension of the strings is immense, often exceeding 20 tons of force. To withstand this pressure, a heavy cast-iron plate is used, a design innovation popularized in the 19th century by manufacturers like Chickering and Steinway. Each of the 88 keys must be balanced with lead weights to ensure a consistent touch across the entire keyboard. This calibration is so sensitive that even minor changes in humidity can affect the wood and felt components.The soundboard, usually made of high-quality Sitka spruce, acts as a mechanical amplifier. It vibrates in response to the strings, moving the air to create the rich resonance we hear. Because every part must work in perfect synchronization, it takes approximately one year to build a high-end concert grand. This intricate assembly remains one of the most sophisticated examples of mechanical physics in the modern world.