control change messages
A MIDI protocol that can send a range of values (0-127) that can modify parameters in MIDI equipment. 0-31 are continuous controllers that you can imagine as MIDI "knobs." 64-95 are on/off controllers that you can imagine as "switches." Some of these messages have predefined uses. Others are undefined and many synthesizers, samplers, and MIDI software programs allow you to assign your own parameters to the MIDI messages. Common MIDI controllers are: #1 modulation wheel, #7 volume, #10 pan, and #64 sustain pedal.