diff --git a/01 - JavaScript Drum Kit/index-START.html b/01 - JavaScript Drum Kit/index-START.html
index 4070d32767..216f789788 100644
--- a/01 - JavaScript Drum Kit/index-START.html	
+++ b/01 - JavaScript Drum Kit/index-START.html	
@@ -57,8 +57,25 @@
   <audio data-key="75" src="sounds/tom.wav"></audio>
   <audio data-key="76" src="sounds/tink.wav"></audio>
 
-<script>
+<script>  
 
+function removeTransition(e) {
+  if (e.propertyName !== 'transform') return;
+  this.classList.remove('playing');
+}
+
+function playSound(e) {
+  const audio = document.querySelector(`audio[data-key="${e.keyCode}"]`);
+  const key = document.querySelector(`.key[data-key="${e.keyCode}"]`);
+  if(!audio) return;
+  audio.currentTime = 0;
+  audio.play();
+  key.classList.add('playing');
+}
+
+const keys = Array.from(document.querySelectorAll('.key'));
+keys.forEach(key => key.addEventListener('transitionend', removeTransition));
+window.addEventListener('keydown', playSound);
 </script>
 
 
diff --git a/02 - JS and CSS Clock/index-START.html b/02 - JS and CSS Clock/index-START.html
index 2712384201..b2991602d0 100644
--- a/02 - JS and CSS Clock/index-START.html	
+++ b/02 - JS and CSS Clock/index-START.html	
@@ -58,15 +58,47 @@
     .hand {
       width:50%;
       height:6px;
+      border-radius: 50%;
       background:black;
       position: absolute;
       top:50%;
+      transform-origin: 100%;
+      transform: rotate(90deg);
+    }
+    .second-hand {
+      background-color: #ffffff;
+    }
+    .min-hand {
+      background-color: #666666;
     }
 
   </style>
 
   <script>
 
+  const secondHand = document.querySelector('.second-hand');
+  const minuteHand = document.querySelector('.min-hand');
+  const hourHand = document.querySelector('.hour-hand');
+
+  function setDate() {
+    const now = new Date();
+    
+    const seconds = now.getSeconds();
+    const secondsDeg =  ((seconds / 60) * 360) + 90;
+    secondHand.style.transform =  `rotate(${secondsDeg}deg)`;
+    if (secondsDeg <= 90) {
+      secondHand.style.transition = 'none';
+    }else{secondHand.style.transition = 'all 0.05s cubic-bezier(0, 2, 0.50, 1)';}
+
+    const minutes = now.getMinutes();
+    const minutesDeg = ((minutes / 60) * 360) + 90;
+    minuteHand.style.transform = `rotate(${minutesDeg}deg)`;
+    
+    const hours = now.getHours();
+    const hoursDeg = ((hours / 12) * 360) + 90;
+    hourHand.style.transform = `rotate(${hoursDeg}deg)`;
+  }
+  setInterval(setDate, 1000);
 
   </script>
 </body>
diff --git a/03 - CSS Variables/index-START.html b/03 - CSS Variables/index-START.html
index ca2b59d077..33e1bad30e 100644
--- a/03 - CSS Variables/index-START.html	
+++ b/03 - CSS Variables/index-START.html	
@@ -21,10 +21,21 @@ <h2>Update CSS Variables with <span class='hl'>JS</span></h2>
   <img src="https://source.unsplash.com/7bwQXzbF6KE/800x500">
 
   <style>
+    :root {
+		--base: #ffc600;
+		--spacing: 10px;
+		--blur: 10px;
+    }
+
+    img {
+    	padding: var(--spacing);
+    	background-color: var(--base);
+    	filter: blur(var(--blur));
+    }
 
-    /*
-      misc styles, nothing to do with CSS variables
-    */
+    .hl {
+    	color: var(--base);
+    }
 
     body {
       text-align: center;
@@ -48,6 +59,19 @@ <h2>Update CSS Variables with <span class='hl'>JS</span></h2>
   </style>
 
   <script>
+  const inputs = document.querySelectorAll('.controls input');
+
+  function handleUpdate() {
+  	const suffix = this.dataset.sizing || '';
+  	const name = this.name;
+  	const value = this.value + suffix;
+  	document.documentElement.style.setProperty(`--${name}`, value)
+  }
+
+  inputs.forEach(input => input.addEventListener('change', handleUpdate));
+  inputs.forEach(input => input.addEventListener('mousemove', handleUpdate));
+
+
   </script>
 
 </body>
diff --git a/04 - Array Cardio Day 1/index-START.html b/04 - Array Cardio Day 1/index-START.html
index eec0ffc31d..ea7c93b561 100644
--- a/04 - Array Cardio Day 1/index-START.html	
+++ b/04 - Array Cardio Day 1/index-START.html	
@@ -32,28 +32,61 @@
     // Array.prototype.filter()
     // 1. Filter the list of inventors for those who were born in the 1500's
 
+    const fifteen = inventors.filter(inventor => inventor.year >= 1500 && inventor.year < 1600);
+    console.table(fifteen);
+
     // Array.prototype.map()
     // 2. Give us an array of the inventors' first and last names
 
+    const fullnames = inventors.map(inventor => `${inventor.first} ${inventor.last}`);
+    console.log(fullnames);
+
     // Array.prototype.sort()
     // 3. Sort the inventors by birthdate, oldest to youngest
 
+    const ordered = inventors.sort((a,b) => a.year > b.year ? 1 : -1);
+    console.table(ordered);
+
     // Array.prototype.reduce()
-    // 4. How many years did all the inventors live?
+    // 4. How many years did all the inventors live? 
+
+    const totalyears =  inventors.reduce((total, inventor) => {
+      return total + (inventor.passed - inventor.year);
+    }, 0);
+
+    console.log(totalyears);
 
     // 5. Sort the inventors by years lived
 
+    const yearslived = inventors.sort((a, b) => (a.passed-a.year) > (b.passed - b.year) ? -1 : 1);
+    console.table(yearslived);
+
     // 6. create a list of Boulevards in Paris that contain 'de' anywhere in the name
     // https://en.wikipedia.org/wiki/Category:Boulevards_in_Paris
 
 
     // 7. sort Exercise
     // Sort the people alphabetically by last name
+    const aToZ = people.sort(function(a, b){
+      const [aLast, aFirst] = a.split(', ');
+      const [bLast, bFirst] = b.split(', ');
+      return aLast > bLast ? 1 : -1;
+    });
+    console.log(aToZ);
 
     // 8. Reduce Exercise
     // Sum up the instances of each of these
     const data = ['car', 'car', 'truck', 'truck', 'bike', 'walk', 'car', 'van', 'bike', 'walk', 'car', 'van', 'car', 'truck' ];
 
+    const collection = data.reduce(function(obj, item){
+      if(!obj[item]){
+        obj[item] = 0;
+      }
+      obj[item]++;
+      return obj;
+    }, {})
+
+    console.log(collection);
   </script>
 </body>
 </html>