diff --git a/01 - JavaScript Drum Kit/index-START.html b/01 - JavaScript Drum Kit/index-START.html
index 4070d32767..3cd35f4e77 100644
--- a/01 - JavaScript Drum Kit/index-START.html	
+++ b/01 - JavaScript Drum Kit/index-START.html	
@@ -59,6 +59,25 @@
 
 <script>
 
+window.addEventListener('keydown', playSound)
+
+const keys = document.querySelectorAll('.key');
+keys.forEach(key => key.addEventListener('transitionend', removeTransition));
+
+function playSound (event) {
+  const audio = document.querySelector(`audio[data-key="${event.keyCode}"]`);
+  const key = document.querySelector(`.key[data-key="${event.keyCode}"]`);
+  if (audio === null) { return null; }
+  audio.currentTime = 0;
+  audio.play();
+  key.classList.add('playing');
+}
+
+function removeTransition (event) {
+  if (event.propertyName !== 'transform') { return null }
+  this.classList.remove('playing');
+}
+
 </script>
 
 
diff --git a/02 - JS + CSS Clock/index-START.html b/02 - JS + CSS Clock/index-START.html
index 2712384201..37b7b43826 100644
--- a/02 - JS + CSS Clock/index-START.html	
+++ b/02 - JS + CSS Clock/index-START.html	
@@ -61,12 +61,35 @@
       background:black;
       position: absolute;
       top:50%;
+      transform-origin: 100%;
+      transform: rotate(90deg);
+      transition: all 0.05s;
+      transition-timing-function: cubic-bezier(0.1, 2.7, 0.58, 1);
     }
 
   </style>
 
   <script>
+  const secondHand = document.querySelector('.second-hand');
+  const minuteHand = document.querySelector('.min-hand');
+  const hourHand = document.querySelector('.hour-hand');
 
+  function setDate () {
+    const today = new Date();
+    const seconds = today.getSeconds();
+    const minutes = today.getMinutes();
+    const hours = today.getHours();
+
+    const secondsDegrees = ((seconds/ 60) * 360) + 90;
+    const minutesDegrees = ((minutes/ 60) * 360) + 90;
+    const hoursDegrees = ((hours/ 12) * 360) + 90;
+
+    secondHand.style.transform = `rotate(${secondsDegrees}deg)`;
+    minuteHand.style.transform = `rotate(${minutesDegrees}deg)`;
+    hourHand.style.transform = `rotate(${hoursDegrees}deg)`;
+  }
+
+  setInterval(setDate, 1000);
 
   </script>
 </body>
diff --git a/03 - CSS Variables/index-START.html b/03 - CSS Variables/index-START.html
index bf0f33e3ba..db1d0c85a3 100644
--- a/03 - CSS Variables/index-START.html	
+++ b/03 - CSS Variables/index-START.html	
@@ -21,6 +21,21 @@ <h2>Update CSS Variables with <span class='hl'>JS</span></h2>
   <img src="https://source.unsplash.com/7bwQXzbF6KE/800x500">
 
   <style>
+    :root {
+      --blur: 10px;
+      --spacing: 20px;
+      --base: #ffc600;
+    }
+
+    img {
+      padding: var(--spacing);
+      background: var(--base);
+      filter: blur(var(--blur));
+    }
+
+    .hl {
+      color: var(--base);
+    }
 
     /*
       misc styles, nothing to do with CSS variables
@@ -53,6 +68,16 @@ <h2>Update CSS Variables with <span class='hl'>JS</span></h2>
   </style>
 
   <script>
+  const inputs = document.querySelectorAll('.controls input');
+  const styleSheet = document.documentElement.style;
+
+  function handleUpdate () {
+    const suffix = this.dataset.sizing || '';
+    styleSheet.setProperty(`--${this.name}`, `${this.value}${suffix}`);
+  }
+
+  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 6e28e357d0..f617279a4c 100644
--- a/04 - Array Cardio Day 1/index-START.html	
+++ b/04 - Array Cardio Day 1/index-START.html	
@@ -27,29 +27,69 @@
 
     // Array.prototype.filter()
     // 1. Filter the list of inventors for those who were born in the 1500's
+    const fifteens = inventors.filter(inventor => inventor.year >= 1500 && inventor.year <1600);
+    console.log(fifteens);
 
     // Array.prototype.map()
     // 2. Give us an array of the inventory first and last names
+    const invFirstLast = inventors.map(inventor => Object.assign({}, {first: inventor.first, last: inventor.last}));
+    console.log(invFirstLast);
 
     // Array.prototype.sort()
     // 3. Sort the inventors by birthdate, oldest to youngest
+    const invSortBirth = inventors.sort((a, b) => a.year - b.year);
+    console.log(invSortBirth);
 
     // Array.prototype.reduce()
     // 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 invSortLived = inventors.sort((a, b) => (a.passed - a.year) - (b.passed - b.year));
+    console.log(invSortLived);
 
     // 6. create a list of Boulevards in Paris that contain 'de' anywhere in the name
     // https://en.wikipedia.org/wiki/Category:Boulevards_in_Paris
+    /**
+    const div = document.querySelector('.mw-category');
+    const streets = Array.from(div.querySelectorAll('a'));
+    const de = streets
+                .map(street => street.textContent)
+                .filter(street => street.included('de'))
+    
+    console.log(de);
+    */
 
 
     // 7. sort Exercise
     // Sort the people alphabetically by last name
+    const peopSort = people.sort((a, b) => {
+      const [prevLast, prevFirst] = a.split(', ');
+      const [nextLast, nextFirst] = b.split(', ');
+
+      return prevLast > nextLast ? 1 : -1;
+    });
+
+    console.log(peopSort);
 
     // 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 counts = data.reduce((dataCount, entry) => {
+      if (dataCount[entry]) {
+        dataCount[entry] ++;
+      } else {
+        dataCount[entry] = 1;
+      }
+      return dataCount;
+    }, {});
+
+    console.log(counts);
+
   </script>
 </body>
 </html>