Musical keyboards

In music, more than one key are pressed at a time to achieve more complex sounds, or chords

Chord (music)

A chord in music is any harmonic set of two–three or more notes that is heard as if sounding simultaneously. These need not actually be played together: arpeggios and broken chords may for many practical and theoretical purposes be understood as chords...

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Computer Keyboards

Chording, with a chorded keyboard

Chorded keyboard

A keyset or chorded keyboard is a computer input device that allows the user to enter characters or commands formed by pressing several keys together, like playing a "chord" on a piano...

 or keyer

Keyer

A keyer is a device for signaling by hand, by way of pressing one or more switches. Modern keyers typically have a large number of switches but not as many as a full-size keyboard; typically between four and fifty. A keyer differs from a keyboard in the sense that there is no "board"; the keys are...

 allows one to produce as many characters, as a QWERTY keyboard, but with fewer keys and less motion per finger, and is thought to alleviate or prevent carpal tunnel syndrome

Carpal tunnel syndrome

Carpal Tunnel Syndrome is an entrapment idiopathic median neuropathy, causing paresthesia, pain, and other symptoms in the distribution of the median nerve due to its compression at the wrist in the carpal tunnel. The pathophysiology is not completely understood but can be considered compression...

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Pointers

Mouse chording

Mouse chording

Mouse chording is the capability of performing actions when multiple mouse buttons are held down, much like a chorded keyboard. Like mouse gestures, chorded actions may lack feedback and affordance and would therefore offer no way for users to discover possible chords without reference...

 allows a user to use a two-button mouse

Mouse (computing)

In computing, a mouse is a pointing device that functions by detecting two-dimensional motion relative to its supporting surface. Physically, a mouse consists of an object held under one of the user's hands, with one or more buttons...

, trackball

Trackball

A trackball is a pointing device consisting of a ball held by a socket containing sensors to detect a rotation of the ball about two axes—like an upside-down mouse with an exposed protruding ball. The user rolls the ball with the thumb, fingers, or the palm of the hand to move a cursor...

, or touchpad

Touchpad

A touchpad is a pointing device featuring a tactile sensor, a specialized surface that can translate the motion and position of a user's fingers to a relative position on screen. Touch pads are a common feature of laptop computers, and they are also used as a substitute for a mouse where desk...

 as if it where a three-button device. For example, in the Unix

Unix

Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...

 graphical user interface

Graphical user interface

In computing, a graphical user interface is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand-held devices such as MP3 players, portable media players or gaming devices, household appliances and...

 (X11), the middle button is used to paste text. Since Microsoft-type mice have only two buttons, users of Unix-type systems such as Linux and BSD chord the right and left buttons to paste text.

Multitouch chording

TipTapSpeech an application for the iPhone and iPad is a chord-based text entry solution for touch screen computing.

A GKOS chording keyboard application development for iPhone was started on the GKOS Google Group on May 25, 2009. The application for iPhone became available on May 8, 2010, and a similar application for Android on October 3, 2010. Thumbs are used to press the keys that are located towards the sides of the screen, either a single key or two keys simultaneously.

Douglas Engelbart, Valerie Landau, Robert Stephenson, Evan Schaffer, Eric Matsuno, and Cherif Algreatly filed a patent in 2010 for a chorded solution for multitouch screens.