From Music Player Daemon Community Wiki

My idea is to include a virtual file:// protocol handler. It could be used to "stream" local files the same way as internet streams are played. Local files and directories could be "dragged" to a graphical mpd client to add them to a playlist and play _without_ adding them to a database.

Be aware: My mpd runs on an differnet machine than the clients. If I "drag" a file to a client the only way to get the file to the server is sending it through the mpd protocoll.