In the following step-by-step guide I demonstrate how to connect a bluetooth MIDI Controller to an USB MIDI Device using a Raspberry Pi as MIDI Host. It should be possible to use this guide to make any Linux (Debian/Ubuntu) System act as a MIDI Host.
In this example I use the following hardware:
[ MIDI Controller ] --> [ MIDI Host ] --> [ MIDI Device ]
[ M-Wave Chocolate ] --> [Raspberry Pi 3B+] --> [Zoom MS-70CDR+]
[ Sender ] --> [ Router ] --> [ Reciever ]