Trying Soundcloud API for the first time but it won't load my tracks

Question

I'm sure that I've done something very simple that wrong but... I've registered an app. Got my client ID and Secret and my code is below. If anyone can give me some pointers I would be most grateful. Regards David

        SC.initialize({
          client_id: '<?php echo $controller->MY_CLIENT_ID; ?>'
        });

        SC.get('/tracks',  function(tracks) {
         var options = '';           
         $.each(tracks, function(key, value) { 
         var optionValue = value.title+'[[CHILD]]'+value.stream_url+'[[CHILD]]'+value.download_url+'[[CHILD]]'+value.stream_url;
         //&& $('#SelectRight_soundcloud option[value='+optionValue+']').length == 0
            if(value.downloadable){
                options = options +'<option value="'+optionValue+'">'+value.title+'</option>';
            }
        });

        $("#SelectLeft_soundcloud").html(options);


        });