How to Stream mp3 files while not allowing downloads

I am building a streaming service, from mp3 files on my own server. While testing, I'm using the the <audio> to stream it, while the file location/path/name is coming in from the database, but I'm not sure if it is the right way to do it. I want to protect the streaming mp3 file from being downloaded, without actually using Flash ( I have read somewhere that file location is embedded inside the swf file, and it's not that easy to download it off there ). What I want to know is how SoundCloud and other streaming websites / app do it in a more secure way. Include articles / links to posts if possible. Thanks! :)