A keyboard instrument is any musical instrument played using a musical keyboard. The most common of these is the piano. Other widely used keyboard instruments include various types of organs as well as other mechanical, electromechanical and electronic instruments. In common language, it is mostly used to refer to keyboard-style synthesizers.
The clavichord and the harpsichord appeared during the 14th century, the clavichord probably being the earlier. During their development, a B-flat key was added to the keyboard in order to remedy the tritone between F and B, and the other semitones were added later. The harpsichord and the clavichord were both very common until the widespread adoption of the piano in the 18th century, after which their popularity decreased. The piano was revolutionary because a pianist could vary the volume (or dynamics) of the sound by varying the vigor with which each key was struck. The piano's full name is "gravicèmbalo con piano e forte" meaning "harpsichord with soft and loud" but can be shortened to "piano-forte", which means "soft-loud" in Italian.
Keyboard instruments were further developed in the 20th century. Early electromechanical instruments, such as the Ondes Martenot, appeared early in the century.
Much effort went into finding an instrument, which sounded like the piano but lacked its size and weight. The electric piano and electronic piano were early efforts that, while being useful instruments in their own right, were not successful in convincingly reproducing the timbre of the piano. Electric and electronic organs were developed during the same period.
Significant development of the synthesizer occurred in the 1960s and has continued ever since. The most notable early synthesizer is the Moog synthesizer, which used analog circuitry. In time, digital synthesis became common.
Tape replay keyboards were invented in the 1940s and saw popularity in the late 1960s and 1970s. The best-known example is the Mellotron. These instruments became obsolete with the invention of samplers, which replay samples at any pitch.
Now Modern-day keyboards have such facilities as colour LCD screens, highly realistic voices and styles and MIDI recording.