buildStream.js

      var stream = {
        tracks: [],
        playlists: []
      };

      function buildStream(group, callback) {
        var artists = group.artists;
        var params = {
          limit: 5
        };

        async.each(artists, getStreamItems, function done(err) {
          if (err) {
            console.log(err);
          }
          callback(stream);
        });

        function getStreamItems(artist, done) {
          Soundcloud.get('/e1/users/' + artist + '/stream', params, processStreamItems);

          function processStreamItems(items) {
            async.each(items, processItem, error);

            function processItem(item, cb) {
              if ((item.type === 'track') || (item.type === 'track_repost')) {
                stream.tracks = stream.tracks.concat(item.track);
              } else if ((item.type === 'playlist') || (item.type === 'playlist_repost')) {
                stream.playlists = stream.playlists.concat(item.playlist);
              }

              cb();
            }

            function error(err) {
              if (err) {
                console.log(err);
              }
            }
            done();
          }
        }
      }