Keyboard instrument

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"Keyboards" redirects here. For other uses of the word, see Keyboard.

A keyboard instrument is any musical instrument played using a musical keyboard. The most common of these is the piano, which is used in nearly all forms of western music. 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.

1 History
2 Electronic keyboards
3 List of keyboard instruments

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History

Among the earliest keyboard instruments are the organ, the clavichord, and the harpsichord. The organ is doubtless the oldest of these, appearing in the 3rd century BC, although this early instrument--called hydraulis--did not use a keyboard in the modern sense. From its invention until the 14th century, the organ remained the only keyboard instrument. Often, the organ didn't feature a keyboard at all, rather buttons or large levers which were operated by a whole hand. Almost every keyboard until the 15th century had 7 naturals to each octave.

The clavichord and the harpsichord appeared during the 14th century, the clavichord probably being the earliest. 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 in the early in the century.

The earliest fully electronic keyboard instruments were electronic organs that used oscillators and frequency dividers, together with a network of filters, to produce waveforms.

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 most well known example is the Mellotron. These instruments became obsolete with the invention of samplers, which replay digital samples at any pitch.

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Electronic keyboards

Image:YamahaKeyboard.jpg An electronic keyboard is any keyboard instrument which uses electronics to produce its sound. Professional electronic musical instruments which are traditionally equipped with a keyboard include electric pianos, electronic pianos, synthesizers, samplers, electronic organs, and digital pianos. However, musicians generally refer to these instruments by name or simply as keyboards, reserving the term electronic keyboard for keyboard instruments marketed to amateur musicians and children. Such instruments are typically inexpensive, smaller, and lack many features offered by professional instruments. They can generally be purchased in electronics stores side by side with stereos, video games, cells phones, etc., or even in toy stores.

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Internal architecture

To facilitate the engineering processes of design and development of electronic keyboards, they are internally divided into some major components which can be connected together by the mean of industry standards. These parts include:

Musical keyboard: This is an electro-mechanical component which is used for playing.
User interface software: A program (usually embedded in a chip) which handle user interaction with control keys and menus.
Rhythm & Chord generator: This part which is again in the form of software program produces rhythms and chords by the mean of MIDI commands.
Sound generator: It’s exactly like a sound module which is capable of accepting MIDI commands and producing sounds accordingly.

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Functions and features

Auto accompaniment
Effects
Demonstration
MIDI: Many electronic keyboard instruments are outfitted with a MIDI interface for the purpose of controlling (or being controlled) by another device with a MIDI interface. There are also keyboards which are not instruments at all, but are merely MIDI controllers which are used to control other MIDI instruments, which may or may not have a human interface of their own. (see sound module)

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Concepts and definitions

Touch response: : To simulate the process of sound generation in chordophones that are sensitive to the velocity of key press, a technology which is usually known as auto-accompaniment is used. For implementation two sensors are installed for each key: a sensor detects whenever a key is beginning to be pressed and the other fired when the key is pressed completely. By a time reference a device can estimate the velocity of pressure. As the key mass is constant this velocity can also be considered as the strength of key press. Based on this value, the sound generator produces the proper sound.

After touch
Polyphony: In digital music terminology and electronic keyboards, polyphony means the number of concurrent notes that can be played at the same time.
Tempo: This is a parameter that determines the speed of rhythms, chords and other auto-generated content on electronic keyboards. The unit of this parameter is beats per second.
Split point
Style
Synchronization

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Parts and controls

Foot pedal/switch
Modulation wheel
Pads
Pitch bend: This control is usually in the form of a wheel located on the left side of the keyboard that is used to shift the frequency of the note being played up or down. The amount of this frequency change is adjustable in some keyboards but it’s usually between one and two semitones up or down. The origin of this control is not from keyboard instruments, but from some string instruments like guitar in which the player can increase the frequency by pushing the string aside.

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