The clavichord had a quiet tone, but the way it was built allowed for some control of dynamics and even vibrato.
Later, the Virginal was developed in the form of a small harpsichord. The virginal's keys were set at a right angle to a single set of stings. When a key was pressed on a virginal, a vertical rod, (also called a jack) holding a leather or quill plectrum rose and plucked the string. This produced a louder tone than the clavichord but lacked its variety in dynamics. The next instrument that evolved was the Spinet. "Though this instrument originated in Italy, it was perfected by English builders in the late seventeenth century" (Grover). This was right about the time of composer Henry Purcell. The jack mechanism plucked the strings just as in the virginal, but the wing shape permitted longer strings. This longer length of the stirrings increased the volume, and expanded the range of the instrument to as much as five octaves.
Recognized as early as the fifteenth century, the harpsichord form, where the keys are in line with the strings, reached its peak in the period of Bach and Handel. In this shape, (also the pattern for the modern grand) the strings were longer, and the instrument sounded louder than the clavichord. In about 1709, Bartolommeo Cristofori built several instruments in the harpsichord shape; however, he built them with hammer mechanisms surprisingly like the modern piano today. Because players could now control soft and loud (piano-forte), which was impossible on earlier plucked keyboard instruments, Cristofori named his new instrument pianoforte. This instrument would be the model in which the modern grand piano would take after (Hamilton).
During the eighteenth century, a double-escapement was introduced by Sebastien Erard in 1821; this allowed fast repetition to be made. Using a cast-iron frame instead of a wooden one was important because it permitted the use of heavier strings.