I knew that I could get my music into Djay from either Spotify or Itunes - so far so good, except that I am looking to dump iTunes in favor of VLC for everything (except iTunes DRM movies, of which I have a few). Somehow I missed the fact that I could get music from other sources than the official Apple player / synced with iTunes world. I discovered the menu item to get stuff from various cloud services, and when I chose “on this iPhone”, I could get to the music I uploaded to VLC! Happy Dance!
I have the FileBrowser App on the phone, which was also listed as an option. I have FileBrowser set up to connect to my NAS via encrypted webdav. Upon authenticating, I was then able to get music off of my NAS collection - 2+ terabytes of music and growing!
I consider it a best practice to download all music I plan to play, whether in Spotify or other, but it is nice to know that I could in a pinch (for a rare request), get to all of my music over the internet if I don’t have it handy.
That leads to another new system that I am loving: A $35 Raspberry Pi in a case with a powered USB hub and a couple of 4TB USB drives connected to my network, and using the OpenMediaVault distro. This creates a NAS box that allows me to get to my files from anywhere and keep them in sync. If I am using the laptop for DJing, I can just grab one of the drives and hook it up to have the mega-local crate. If I leave it at home, I can still get to the music. Sweet!