function displayWaveForms(svg) {
    var waveformElements = document.querySelectorAll(".amplitude-wave-form");

    /*
      Iterate over all of the waveform elements and
      display the waveform.
    */
    for (var i = 0; i < waveformElements.length; i++) {
      /*
        Get the playlist attribute of the waveform element.
      */
      var playlist = waveformElements[i].getAttribute("data-amplitude-playlist");

      /*
        Get the song index attribute of the waveform element.
      */
      var song = waveformElements[i].getAttribute("data-amplitude-song-index");

      /*
        If the playlist is null and the song is null it's a global element.
      */
      if (playlist == null && song == null) {
        displayGlobalWaveform(waveformElements[i], svg);
      }

      /*
        If the playlist is defined but the song is null it's a playlist element.
      */
      if (playlist != null && song == null) {
        displayPlaylistWaveform(waveformElements[i], svg, playlist);
      }

      /*
        If the playlist is not defined and the song is not null it's a song
        element.
      */
      if (playlist == null && song != null) {
        displaySongWaveform(waveformElements[i], svg, song);
      }

      /*
        If the playlist and song are defined it's a song in the playlist element.
      */
      if (playlist != null && song != null) {
        displaySongInPlaylistWaveform(waveformElements[i], svg, playlist, song);
      }
    }
  }
Displays all of the waveforms necessary.

@param {path} svg - The drawing of the waveform.