Foobar2000 plugin to synchronize playlist with contents of specified directories.
Latest version: 4.1
In the Preferences window click on "Playlist Bind" under the Tools sub-menu. Here you can highlight a playlist and click add (the green plus button). From there you can choose which directory you want to bind that playlist to.
To update your playlist click "Bind" under the file menu. Here you can choose to update (only update the current playlist), or update all (update all bound playlists).
You may also set the bind commands to a keyboard shortcut.