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MIDI

isobar-ext's MIDI support is based on the excellent mido library.

Two classes are available for MIDI I/O:

MidiOutputDevice

Sends note and control events to a MIDI device. isobar-ext can also act as the clock out, so that external MIDI devices follow isobar's internal clock.

Virtual MIDI devices

To control a MIDI device on the same computer that is running isobar, you will need to create a virtual MIDI bus.

name = "My MIDI Device Name"
midi_out = iso.MidiOutputDevice(device_name=name,
                                send_clock=True)
timeline = Timeline(tempo=120, output_device=midi_out)
  • device_name: Specifies the device name to search for. Leave empty to use the system default.
  • send_clock: If True, sends clock sync signals to the external device.

A default MIDI output device name can be set with an environmental variable:

export ISOBAR_DEFAULT_MIDI_OUT="Prophet 6"

To list all available MIDI output devices:

print(iso.io.midi.get_midi_output_names())

MidiInputDevice

Receives notes and control events from a MIDI device, or sync isobar to an external MIDI clock.

# Receive MIDI messages from an external device 
name = "My MIDI Device Name"
midi_in = iso.MidiInputDevice(device_name=name)

# Blocking mode: waits until a message is received
message = midi_in.receive()

# Non-blocking: if a message is available, return it; otherwise, return None
message = midi_in.poll()

# Sync a Timeline to a MIDI external clock 
name = "My MIDI Device Name"
midi_in = iso.MidiInputDevice(device_name=name)
timeline = Timeline(tempo=120, clock_source=midi_in)

A default MIDI input device name can be set with an environmental variable:

export ISOBAR_DEFAULT_MIDI_IN="Prophet 6"

To list all available MIDI input devices:

print(iso.io.midi.get_midi_input_names())