gistfile1.txt

const script = document.createElement('script');
script.type = 'text/javascript';
script.src = 'https://cdnjs.cloudflare.com/ajax/libs/tunajs/1.0.4/tuna-min.js';
document.head.appendChild(script);

const apply = () => {
  const context = new AudioContext();
  const tuna = new Tuna(context);

  const filter = new tuna.Filter({
    frequency: 440,
    Q: 80,
    gain: 0,
    filterType: 'bandpass',
    bypass: 0
  })

  const overdrive = new tuna.Overdrive({
    outputGain: 0,
    drive: 1,
    curveAmount: 0.65,
    algorithmIndex: 2,
    bypass: 0
  })

  let source;
  const gain = context.createGain();

  gain.gain.value = 0.05
  overdrive.connect(filter)
  gain.connect(overdrive);
  filter.connect(context.destination);

  const audioTags = document.getElementsByClassName("m-audio")

  for (i=0; i<audioTags.length; i++) {
    let audio = audioTags[i].firstChild
    source = context.createMediaElementSource(audio);
    source.mediaElement.playbackRate = 1.3
    source.connect(gain);
  }
}

setTimeout(apply, 1000);