Maybe you aren't 100% clear on what Subsonic is/offers...
It is, in essence, a streaming service. It allows you to make your collection available over the internet to any client/player that is able to connect to it. Think of the following real-life scenario (my own):
- I have a huge collection of music I have amassed over the years. It's located in my home NAS.
- When I'm home, I use MusicBee to manage that collection. I listen to music, edit tags, organize etc.
- When I'm not at home, I want to be able to access that collection as well - that's where Subsonic comes in.
I have installed Subsonic on a spare machine which is always-on. I have configured Subsonic to use my collection located in my home NAS, the same way I did for MusicBee (just point it to the right folders, and Rescan).
Now when I'm on the road, I can use a mobile App to access my Subsonic server and stream any song from my collection directly to my phone. I can use "D-Sub" (an Android app) for that.
When I'm at work, I wanted to be able to do the same with a desktop client (e.g. MusicBee). I could just use the web interface that Subsonic provides, but I found that it's not ideal if you're also using the browser doing other things - the stream can chop up sometimes due to the browser doing heavy work on another tab for example.
And that brings us to the plugin - it allows a MusicBee installation to tap into a Subsonic server. In my case, my home server with my collection.
Using the plugin, MusicBee "sees" an extra library with content which it can manipulate in the same way as a local one - i.e. search, playback, etc.
Subsonic itself allows more functionality than what the plugin has implemented so far, such as editing the Tags, downloading media locally, uploading media to the server/collection, even Chatting with other users currently connected on your Subsonic server. Some of that functionality I'm planning to add to the plugin in the future. Feedback and suggestions would also dictate what parts will be done first.
For example, my first item in the to-do list is to change the way the plugin connects to the Subsonic server: it currently sends your password as plaintext, I will change that to use a one-time token instead for better security.
I hope this makes things a bit more clear...
Let me know if you have any more questions.