Keyboard instruments have undergone many changes through the years. In its early form, keyboards only had natural notes, but by the 15th century it had become chromatic.
The clavichord is believed to be the descendant of the monochord. The word "clavichord" comes from the Latin word clavis
meaning "key" and chorde
which means "string". During the latter half of the 18th century, interest on the clavichord was revived when composers like Carl Philip Emanuel Bach wrote pieces for it.
Not much is known about the harpsichords' early history. This wing-shaped instrument is believed to have emerged from the psaltery - a hand-held instrument that is plucked by a plectrum. Many Baroque composers, like J.S. Bach and Jean-Philippe Rameau, wrote for or played the harpsichord.
Most of the famous classical composers were piano virtuosos, such as Mozart and Beethoven. Today, the piano remains one of the most popular musical instruments for both children and adults.