Hi all,
When I worked with Windows I first Media Monkey and later MusicBee as a media organizer for my large music collection. Now that I'm on Linux OS I have been searching and testing more than 10 media organizers and came to the conclusion that gmb is absolutely the best of them all! The one thing I really do miss in all Linux media organizers, including gmb,  is that you don't have the option of automatic add and organize new music files. In both Media Monkey and MusicBee you have the option to let the software at the start-up watch a given folder for newly added files. If files are found, they will be automatically organized into folders and file names according to your own rules. They will then be moved to your standard music folder and added to your database.  As far as I know in all Linux organizers you have to do all the adding and organizing by hand, which is really a pain in the ass when you have to add files to a folder that contains thousands of sub-folders and files on a external hd (soooo....slow). I know you can check in gmb for added/delete titles, but that also takes up lot of time when you have a huge collection. It is much faster and more efficient when the software has to check only one folder for a few newly added files (instead checking of tens of thousands files for changes.)
Is it possible to implement some kind of tool or plugin that automatically watches one folder at start-up (where you add your new files) and automatically adds the files to your standard music folder and database, in the structure as laid down in the way you want to organize them in folders/sub-folders/files.

I've tried that under wmp, media monkey and itunes (not much cause it sucks) but was never able to get anything as satisfying as manual check/tagging.
So I imagine what you ask is for something really simple like tagging the "Album Artist" and "Album" of every song in your input folder and then push a button that would create folders and move files into the correct ones.

If yes you can do that manually: In gMB select all the files from that input folder and then right click -> mass rename, you'll have options to rename files based on tags, and get them sorted in a base folder of your choosing with the tree structure you want (E.g. Genre - AlbumArtist - Album).

You spoke of automatically doing that, I have no idea how that would work. Since the tags are often incorrect or missing (at the very least don't respect your personal tree hierarchy), automatically dispatching these into new unchecked folders would make the same mess in your folders as the programs I used under windows did, you don't want that. E.g. if your new files are from 2 different friends, one that utilizes the "Album Artist" tag while the one that uses itunes probably doesn't. That in itself is prone to poop all over your library, I've been there. So first label correctly to your liking, then mass rename. That should do it fine...

If I completely or partially missed your point, reply. I might check back :D

Sorry for not replying sooner.
Personally I prefer moving the files myself. But of course I guess that's a feature that some people would like.
As sinekonata said, often new files are not correctly tagged (at least not as you want them to be). In addition to that the current code to move/rename files could use some improvements, in particular if multiple songs are renamed into the same name (which can easily happen with missing tags) you will get a lot of dialogs asking you what to do.
I'll probably add this feature, maybe as a plugin, when I improve the move/rename code. Also it should become possible via a command once I implement the new command system. Of course I've been rather slow lately, so I don't know when that will be.

In the meantime, some advices to make it better :
- you can add songs without scanning the whole library, when using the menu (not all layouts have a menu) Main->"adding files/folders" allows you to add a folder without adding that folder to the list of folders in the preferences. I use that with a file dialog where folders are sorted by last modified time to add the new files.
- you could put only the folder where you put new music in the list of folders to scan, scan it automatically on startup, and from time to time move/rename all those new files using the mass-rename dialog (I need to rename/reorganize the rename/move/copy dialogs). That will come rather close to what you want I think.