Virtual MIDI and Bitwig

I recently discovered that there are two types of MIDI under Linux:
SEQ and RAW

Bitwig recognises RAW midi which means it can't see virtual devices.

Run:
sudo modprobe snd_virmidi midi_devs=1

Then:
aconnect -l

This should show the virtual MIDI port, something like:
client 16: 'Virtual Raw MIDI 0-0' [type=kernel,card=0]
0 'VirMIDI 0-0 '

You can now send SEQ midi to this port (client 16) and Bitwig can detect client 16, which should appear as a Virtual MIDI

You may need to use something like qpwgraph to wire your SEQ MIDI output to the virtual MIDI input:
sudo apt install qpwgraph

To persist the virtual midi changes run:
sudo echo snd-virmidi >> /etc/modules

sudo vim /etc/modprobe.d/snd-virmidi.conf

And in that file put:
options snd-virmidi midi_devs=1