【完全コピペ可能】Web Audio APIで音鳴らしてみた。ついでに停止、再開ボタンも。

<button id="bgmConfirm" ontouchstart="">開始</button>
<button id="bgmStop" ontouchstart="">停止・再開</button>

document.addEventListener("DOMContentLoaded", function(){
    var stopflag=0;
    document.querySelector('#bgmConfirm').addEventListener('click', function() {
      const AudioContext = window.AudioContext || window.webkitAudioContext;
      const ctx = new AudioContext();
      const request = new XMLHttpRequest();
      const url = 'https://zprodev.github.io/web-audio-test/assets/Campfire_Song.mp3';
      request.open('GET', url, true);
      request.responseType = 'arraybuffer';
      request.onload =  () => {
        ctx.decodeAudioData(request.response, (audioBuffer) => {
          const audioSource = ctx.createBufferSource();
          audioSource.buffer = audioBuffer;
          audioSource.connect(ctx.destination);
          audioSource.start();
        });
      }
      request.send();
      // 停止
      document.querySelector('#bgmStop').addEventListener('click', function() {
          if (stopflag == 0) {
              ctx.suspend();
              stopflag = 1;
          } else {
              ctx.resume();
              stopflag = 0;
          }
      });
    });
},false);