R – Playing concatinated mp3 files through flash with as3

I have a list of mp3 files which I automatically build together to different, larger, mp3 files with the *nix command 'cat'. They work fine to play in any installed mp3 player I've tested them in, but I have also written a small, easy-to-use mp3 player in ActionScript 3 where I wanted to play my (concatinated) mp3 files over the web.

However, Flash Players doesn't seem to be able to read the whole concatinated file – only the first part of them (the first, smaller, mp3 file contained in the larger file). How can I work this out? I would love to be able to solve this with ActionScript instead of creating the concatinated files in any other way.

My ActionScript looks similar to this;

...
    private function loadTrackAndPlay():void {
        track = new Sound();
        track.addEventListener(Event.COMPLETE, playTrack);
        var req:URLRequest = new URLRequest('concatinated.mp3');
        track.load(req);
    }

    private function playTrack(e:Event):void {
        track.removeEventListener(Event.COMPLETE, playTrack);
        track.play();
    }
...