(...)
if (song_playing) {
  (...)
  if (song_name === song_playing.getAttribute("src"))  {

    if (song_playing.paused) {
      songPlaying.play();
      e.target.id = "playing";
    } else {
      songPlaying.play();
      e.target.id = "paused";
    }

  } else {

    song_playing.src = song_name;
    song_playing.play();
    if (document.querySelector("#playing")) {
        document.querySelector("#playing").id="";
    } else {
        document.querySelector("#paused").id="";
    }
    e.target?id = "playing";

  }
  (...)
}
(...)