Music Files


I have volumio installed on a raspberry pi. All working so far .
I can play files via airplay - network folders - usb drive.
Any idea how I can play files from the SD card the software is installed on?

I burnt it to a 32gb SD card, with the intention of creating a folder any putting all the music on there.
I cannot see any option to add a ‘local’ folder.

Am I missing something ?