Notes

an instrument with a better dynamic response than the harpsichord
*from 1790 to mid 1800's piano technology and sound was greatly improved due to the new high quality steel called piano wire and the ability to precisely cast iron frames . its tonal range increasing from the five octaves of the piano forte to the seven and more octaves found on modern pianos.
*The complexity of designing, a mechanism activated by a key lever, could cause a hammer not only to strike a string but rebound instantly, allow the string to keep vibrating even when the finger is held down, stop the sound at will, recover quickly for a new stroke, and permit control of a wide range of dynamics by merely varying the finger pressure, must have been enormous. Yet Cristofori not only solved all of these problems, but even incorporated dual strings for each note, a damper pedal (actually a knee lever), and a shift mechanism that permitted the hammers to strike only one of each pair of strings, exactly like our modern una corda pedal. And by 1726, the date of the latest of his instruments still in existence, his action mechanism had been perfected to the point where it was astonishingly similar to the basic design found today in every Steinway, Bosendorfer, Bechstein, and Yamaha.