(1) Devices which generate MIDI messages and which typically resemble musical instruments such as keyboards, guitars, drums, etc. Although originally conceived with a keyboard paradigm, MIDI controllers are now available as guitars, wind valves, drum kits, xylophone, piano, accordion, the violin family, as well as keyboards of all types.
(2) MIDI Controller messages are a type of Channel Voice message designed for adjusting individual controls, such as pan position or channel volume, on equipment in the MIDI network. While not a part of the MIDI specification, certain conventions exist. The table below gives some of the more common controller numbers. See also controller change, continuous controllers, switched controllers. Controller messages can be switched, i.e., their value is either On or Off, or they can be continuous. Controller messages 0-31 take one additional data byte and can therefore carry values in the range 0-127. However, these can be paired with controllers 32-63 to provide two bytes of resolution, e.g., Controller 4 is paired with Controller 36). When this is done, the controller in the range 0-31 takes the MSB and its pair in the range 32-63 takes the LSB, for a range of 16,384 possible values. Most continuous controllers carry values ranging upward from 0, although physical controllers that center around zero (such as balance, pan, and pitch-bend) may be implemented so that their associated controller message carries values centered on the midpoint.
