Local mp3 from Volumio

I just installed Volumio on Raspberry Pi 3.
This raspberry is connected to the sound system in the cinema that i work in and the music from only this one raspberry pi is playing in all of the auditorium in the cinema.
Everything works fine and i put some music on mp3 format to usb stick and it is playing and works very well so there is not problem at all.
However, when i want to replace the music for new music. I will just switch the pi off and take the usb stick out and replace the music in a windows computer. Then i go back and turn it on again and start playing.

Is is possible to load new music into eather the pi itself (the SD card) or the usb though some ftp transfer (ofcaurse local lan)
So i was just wondering if i would upload new music without needing to have physical access to the raspberry or am i always going to need to shut the pi down and remove the usb stick to replace music?

Volumio will be visible in Windows Network, allowing you to transfer files to it (on internal memory or USB)