diff --git a/README.md b/README.md
index 3d1b607..c720740 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,7 @@ You can use it as-as, or integrate it into your existing framework.
 
 At its heart it's composed of
 just two, short, independent functions: `makeSound` and `soundEffect`. The `makeSound` function helps you
-load and play sound files (mp3, wav, ogg, and webm). The `soundEffect`
+load and play sound files (mp3, mp4, wav, ogg, and webm). The `soundEffect`
 function helps you generate a wide range of sound and music effects
 from pure code.
 These two functions are completely modular and free of dependencies, so
@@ -46,7 +46,8 @@ method's array. Then assign a callback function to `sounds.whenLoaded`.
 sounds.load([
   "sounds/shoot.wav", 
   "sounds/music.wav",
-  "sounds/bounce.mp3"
+  "sounds/bounce.mp3",
+  "sounds/wapo_march.m4a"
 ]);
 
 //Assign the callback function that should run
@@ -84,6 +85,7 @@ they're easier to work with:
 var shoot = sounds["sounds/shoot.wav"],
     music = sounds["sounds/music.wav"],
     bounce = sounds["sounds/bounce.mp3"];
+    bounce = sounds["sounds/wapo_march.mp4"];
 ```
 You now have three sound objects, `shoot`, `music`, and `bounce` that
 you can play and control.
diff --git a/index.html b/index.html
index 1194ee0..4efe452 100644
--- a/index.html
+++ b/index.html
@@ -28,8 +28,9 @@
 		</ul>
 	</p>
 	<p>
-		<a href="javascript:sounds['sounds/bounce.mp3'].play();">hyperlink trigger (bounce)<a/>
+		<a href="javascript:sounds['sounds/bounce.mp3'].play();">Hyperlink trigger #1 (bounce)<a/>
 		<button id="btn_some_trigger">Button Trigger (bounce + bonus)</button>
+		<a href="javascript:sounds['sounds/wapo_march.m4a'].play();">Hyperlink trigger #2 (wapo march)<a/>
 	</p>
 <script>
 
@@ -42,7 +43,8 @@
 sounds.load([
   "sounds/shoot.wav", 
   "sounds/music.wav",
-  "sounds/bounce.mp3"
+  "sounds/bounce.mp3",
+  "sounds/wapo_march.m4a"
 ]);
 
 //Assign the callback function that should run
diff --git a/sound.js b/sound.js
index b733f99..01444b7 100644
--- a/sound.js
+++ b/sound.js
@@ -159,7 +159,7 @@ Thank you, Chris!
 
 var exports = {};
 if (window['module'] && module.exports) {
-	exports = module.exports = {};
+  exports = module.exports = {};
 }
 
 /*
@@ -188,7 +188,8 @@ call a `setup` method when all the files have finished loading:
     sounds.load([
       "sounds/shoot.wav",
       "sounds/music.wav",
-      "sounds/bounce.mp3"
+      "sounds/bounce.mp3",
+      "sounds/wapo_march.m4a"
     ]);
     sounds.whenLoaded = setup;
 
@@ -197,6 +198,7 @@ You can now access these loaded sounds in your application code like this:
 var shoot = sounds["sounds/shoot.wav"],
     music = sounds["sounds/music.wav"],
     bounce = sounds["sounds/bounce.mp3"];
+    march = sounds["sounds/wapo_march.m4a"];
 
 */
 
@@ -206,7 +208,7 @@ var sounds = {
   loaded: 0,
 
   //File extensions for different types of sounds.
-  audioExtensions: ["mp3", "ogg", "wav", "webm"],
+  audioExtensions: ["mp3", "ogg", "wav", "webm","m4a","aac"],
 
   //The callback function that should run when all assets have loaded.
   //Assign this when you load the fonts, like this: `assets.whenLoaded = makeSprites;`.
diff --git a/sounds/wapo_march.m4a b/sounds/wapo_march.m4a
new file mode 100644
index 0000000..a76cd29
Binary files /dev/null and b/sounds/wapo_march.m4a differ