Message Types

Supported Messages

Name Keyword Arguments / Attributes
note_off channel note velocity
note_on channel note velocity
polytouch channel note value
control_change channel control value
program_change channel program
aftertouch channel value
pitchwheel channel pitch
sysex data
quarter_frame frame_type frame_value
songpos pos
song_select song

quarter_frame is used for SMPTE time codes. See:

Parameter Types

Name Valid Range Default Value
channel 0..15 0
frame_type 0..7 0
frame_value 0..15 0
control 0..127 0
note 0..127 0
program 0..127 0
song 0..127 0
value 0..127 0
velocity 0..127 64
data (0..127, 0..127, …) () (empty tuple)
pitch -8192..8191 0
pos 0..16383 0
time any integer or float 0


Mido numbers channels 0 to 15 instead of 1 to 16. This makes them easier to work with in Python but you may want to add and subtract 1 when communicating with the user.

velocity is how fast the note was struck or released. It defaults to 64 so that if you don’t set it, you will still get a reasonable value. (64 is the recommended default for devices that don’t support it attack or release velocity.)

The time is used in MIDI files as delta time.

The data parameter accepts any iterable that generates numbers in 0..127. This includes:

mido.Message('sysex', data=[1, 2, 3])
mido.Message('sysex', data=range(10))
mido.Message('sysex', data=(i for i in range(10) if i % 2 == 0))

For details about the binary encoding of a MIDI message, see: