In the 1820's a process was invented for refining steel, used to make a cast iron frame for the piano's sounding-board, replacing wood frames, and creating a new and powerful instrument. By cross-stringing the bass and treble strings the heavy tension of the thicker strings was distributed across the whole frame. The "harp" of the piano could now hold up to 30 tons (60,000 lbs.) of pressure without having the sounding board crack. A second invention allowed pianists to rapidly repeat notes despite the long 'action' of the key work.
This is the instrument of the Romantic period, played by eccentric geniuses such as Brahms, Beethoven and Chopin. With 88 keys and nearly 12,000 parts, the modern concert grand piano contains the full range of the sound of the orchestral instruments from the lowest to the highest, and more than the full range of the lowest and highest human voices. A full length grand piano with a 12' harp creates enormous resonance. Even a small 4.5" grand produces a large volume of sound. The pianos below are links.
