Midi I/O using Python3.

Install Python rtmidi globally on Debian.

sudo apt install python3-rtmidi

mkdir -p ~/src && cd ~/src
git clone https://github.com/SpotlightKid/python-rtmidi
cd python-rtmidi/examples

python3 sequencer/sequencer.py
Creating MidiOut object.
Do you want to create a virtual MIDI output port? (y/N) n
Available MIDI ports:

[0] Midi Through:Midi Through Port-0 14:0
[1] Origin25:Origin25 MIDI 1 16:0
[2] E-MU XMidi2X2:E-MU XMidi2X2 Midi Out 1  20:0
[3] E-MU XMidi2X2:E-MU XMidi2X2 Midi Out 2  20:1

Select MIDI output port (Control-C to exit): 3
Opening MIDI output port #3 (E-MU XMidi2X2:E-MU XMidi2X2 Midi Out 2  20:1).