Hello Tommarr.
To save your MIDI song file onto Genos do this:
1. Press Song B on the home screen.
2. At the left of the screen press on your USB stick, for instance USB1.
3. Find the file you want to copy to Genos.
4. Press file at the top of the screen, and copy the file to Genos.
Yamaha keyboards have a file masking system, so all folders will show on your USB stick, but only MIDI files will show up, other files will not be visible.
Hope this helps