MIDI Channel Voice Messages

All MIDI status byte and data byte values are in hexadecimal

 

MIDI Channel Voice Messages
Status
Byte 		Data
Bytes 		Message Description
8n kk vv Note off Normally sent when a key (on a synthesizer) is released (note 1)
  Value Range Description
  n 0-F MIDI Channel 0 = Ch 1
  kk 00-7F Key which was released
This must correspond to a previous note-on message for correct operation 		3C = Middle-C
  vv 00-7F Velocity with which key was released
Devices which are not velocity sensitive should send vv=40

The interpretation of this message is up to the receiving MIDI device

00=min
40=default
7F=max
Status
Byte 		Data
Bytes 		Message Description
9n kk vv Note on Normally sent when a key (on a synthesizer) is pressed

A corresponding note-off message must be sent for each and every note-on message

  Value Range Description
  n 0-F MIDI Channel 0 = Ch 1
  kk 00-7F Key which was pressed
Each value is a 'half-step' above or below the adjacent values 		3C = Middle-C
  vv 00-7F Velocity with which key was pressed
Devices which are not velocity sensitive should send vv=40

By definition, a note-on message with vv=0 is equivalent to the message: "note-off vv=40" (note 2)

00=note-off (40)
01=ppp
40=mf
7F=fff
Status
Byte 		Data
Bytes 		Message Description
An kk ww Polyphonic Key Pressure Also known as Aftertouch. This message is sent when there is a change in the pressure being applied to a key (ie on a per-key basis).
  Value Range Description
  n 0-F MIDI Channel 0 = Ch 1
  kk 00-7F Key which was pressed
Each value is a 'half-step' above or below the adjacent values 		3C = Middle-C
  ww 00-7F Pressure with which key is being pressed 00=min, 7F=max
Status
Byte 		Data
Bytes 		Message Description
Bn cc nn Controller Change Sent when a change is made in a footswitch, expression pedal, slider, or other controller.
  Value Range Description
  n 0-F MIDI Channel 0 = Ch 1
  cc 00-77 Controller Number see detailed descriptions
  nn 00-7F Controller Value 00=min, 40=center, 7F=max
Status
Byte 		Data
Bytes 		Message Description
Cn pp Program Change
 Used to change the instrument (or sound) to be played when a note-on message is received.
This is usually not retro-active, and only applies to subsequent note-on messages
This message may have a completely different interpretation depending on the type of device. For example, it could change the current rhythm on a drum-machine.
  Value Range Description
  n 0-F MIDI Channel 0 = Ch 1
  pp 00-7F New Program number 00=1st program
Status
Byte 		Data
Bytes 		Message Description
Dn ww Channel Key Pressure Also known as Aftertouch. This message is sent when there is a change in the overall pressure being applied to the keyboard (ie for the channel overall, and not on a per-key basis).
  Value Range Description
  n 0-F MIDI Channel 0 = Ch 1
  ww 00-7F Channel Pressure Value 00=min, 7F=max
Status
Byte 		Data
Bytes 		Message Description
En lsb msb Pitch Bend Sent when a change is made in a pitch-bender lever.
  Value Range Description
  n 0-F MIDI Channel 0 = Ch 1
  lsb 00-7F Least significant byte 00=min, 00=center, 7F=max
  msb 00-7F Most Significant Byte 00=min, 40=center, 7F=max

Footnotes

Note 1
Just because a device has received a note-off message does not automatically imply that the note should cease abruptly. Some sounds, such as organ and trumpet sounds will do so. Others, such as piano and guitar sounds, will decay (fade-out) instead, albeit more quickly after the note-off message is received.
Note 2
Sending note-on with vv=0 improves the effectiveness of Running Status. Hence this message is preferred over the regular note-off message for devices which do not detect release velocity.

 

  
MIDI Channel Voice Messages
The table below presents a summary of the MIDI Channel Voice Message codes in binary form.
A MIDI channel voice message consists of a Status Byte followed by one or two Data Bytes.
Status Byte Data Byte 1 Data Byte 2 Message Legend
1000nnnn 0kkkkkkk 0vvvvvvv Note Off n=channel* k=key # 0-127(60=middle C) v=velocity (0-127)
1001nnnn 0kkkkkkk 0vvvvvvv Note On n=channel k=key # 0-127(60=middle C) v=velocity (0-127)
1010nnnn 0kkkkkkk 0ppppppp Poly Key Pressure n=channel k=key # 0-127(60=middle C) p=pressure (0-127)
1011nnnn 0ccccccc 0vvvvvvv Controller Change n=channel c=controller v=controller value(0-127)
1100nnnn 0ppppppp [none] Program Change n=channel p=preset number (0-127)
1101nnnn 0ppppppp [none] Channel Pressure n=channel p=pressure (0-127)
1101nnnn 0ccccccc 0fffffff Pitch Bend n=channel c=coarse f=fine (c+f = 14-bit resolution)

*The last four bits of a status byte signify the MIDI channel (1-16) the message is intended for offset by 1 [0000=channel #1, 1111=channel #16]

An example of a MIDI channel voice message would be:

10010001 00111100 01000000

The first four bits of the status byte specify the Note On command, while the last four specify MIDI channel #2. The first data byte specifies the key number for middle C (=60 decimal), while the second data byte specifies a median velocity (= 64 decimal).

Running Status
 
MIDI's Running Status allows a single status byte's action to remain in effect for an unlimited number of data byte pairs which follow. For example, to play three notes on the same MIDI channel, a Note On status byte can be sent, followed by six data bytes (key # + velocity of note 1, key # + velocity of note 2, key # + velocity of note 3). To help minimize excessive data by using running status, the Note On command can also function to turn notes off by sending a velocity value of zero for the key # to be turned off.
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