Play only one track at a time. When one track plays, pause the rest.

solo.js

// gist.github.com/ryanve/8703402
// Play only one track at a time.
(function(doc, tags) {
  var listen = 'addEventListener', some = tags.some, pause = function(e) {
    this !== e && !this.ended && !this.paused && !e.ended && !e.paused && e.pause();
  };
  some && listen in doc && tags.some(function(tag) {
    var live = doc.getElementsByTagName(tag), solo = function() {
      some.call(live, pause, this);
    };
    some.call(live, function(e) {
      e[listen]('playing', solo, false);
    });
  });
}(document, ['audio']));