function syncSong(hours) {
    if (_config2.default.active_playlist == null) {
      var durationHourSelectors = document.querySelectorAll('.amplitude-duration-hours[data-amplitude-song-index="' + _config2.default.active_index + '"]');

      for (var i = 0; i < durationHourSelectors.length; i++) {
        var playlist = durationHourSelectors[i].getAttribute("data-amplitude-playlist");

        if (playlist == null) {
          durationHourSelectors[i].innerHTML = hours;
        }
      }
    }
  }
Syncs the song duration hours.

@param {Integer} hours - The duration hours for the audio.