A special MIDI message used to turn of any notes that might be playing on a MIDI instrument. It is often used to recover from erroneous stuck notes that may be playing due to a fault elsewhere in the system. Some MIDI equipment has an associated button called a Panic Button that generates the all-notes-off message and broadcasts it over all MIDI channels. Sometimes an all-notes-off command can be used to stop an instrument from sounding before some specific commands are issues, such as patch change commands.
