Riva:
I'm worried your idea will run into problems as you cannot sync the scanning between the MAX7219 chips. I foolishly think the below maybe betterwork as your not connecting between driver chips. I only drew one led as I'm meant to me working.
Oh right, diodes! I didn't think of that, thanks!
This is getting a way too complex for me. I'll never be able to tone transfer something like this 
About ready to give up on the idea....
