What are the differences and similarities between an upright and a grand piano?

looney_tunes

"The piano is a musical instrument played by means of a keyboard. ... Pressing a key on the piano's keyboard causes a felt-covered hammer to strike steel strings. The hammers rebound, allowing the strings to continue vibrating at their resonant frequency. These vibrations are transmitted through a bridge to a sounding board that couples the acoustic energy to the air so that it can be heard as sound. When the key is released, a damper stops the string's vibration. ... In grand pianos, the frame and strings are horizontal, with the strings extending away from the keyboard. ... Upright pianos, also called vertical pianos, are more compact because the frame and strings are vertical. The hammers move horizontally, and are returned to their resting position by springs, which are prone to wear and tear. Upright pianos with unusually tall frames and long strings are sometimes called upright grand pianos. Some authors classify modern pianos according to their height and to modifications of the action that are necessary to accommodate the height." http://en.wikipedia.org/wiki/Piano Sep 25 10, 4:01 AM