Keyboard matrix circuit

Most electronic keyboards use a keyboard matrix circuit in which the rows and columns are made up of wiring. On electric and electronic keyboards, there is an electric switch under each key. Depressing a key connects a circuit, which causes the tone generation mechanism to be triggered.

Without a matrix circuit, a 61-key keyboard would have to have 61 wires into the integrated circuit of the keyboard. With the matrix circuit, the entire keyboard can send signals to the integrated circuit with two matrices of eight wires that are conceptually arranged into columns and rows. The keyboard controller scans all all of the columns, to determine if a key has been pressed. If a key in the column has been pressed, then the controller scan the rows, to determine which row has been activated. In a manner analogous to the children's board game "Battleship!", the keyboard controller determines which key has been pressed, and then closes the switch for that key's note. This entire process takes place so quickly that the performer is not aware of the delay.