Indicates that a particular note should be released. Essentially, this means that the note stops sounding, but some patches might have a long VCA release time that needs to slowly fade the sound out. Additionally, the device's Hold Pedal controller may be on, in which case the note's release is postponed until the Hold Pedal is released. In any event, this message either causes the VCA to move into the release stage, or if the Hold Pedal is on, indicates that the note should be released (by the device automatically) when the Hold Pedal is turned off. If the device is a MultiTimbral unit, then each one of its Parts may respond to Note Offs on its own channel. The Part that responds to a particular Note Off message is the one assigned to the message's MIDI channel.
0x80 to 0x8F where the low nibble is the MIDI channel.
Two data bytes follow the Status.
The first data is the note number. There are 128 possible notes on a MIDI device, numbered 0 to 127 (where Middle C is note number 60). This indicates which note should be released.
The second data byte is the velocity, a value from 0 to 127. This indicates how quickly the note should be released (where 127 is the fastest). It's up to a MIDI device how it uses velocity information. Often velocity will be used to tailor the VCA release time. MIDI devices that can generate Note Off messages, but don't implement velocity features, will transmit Note Off messages with a preset velocity of 64.
An All Notes Off controller message can be used to turn off all notes for which a device received Note On messages (without having received respective Note Off messages).