diff --git a/01 - JavaScript Drum Kit/index-START.html b/01 - JavaScript Drum Kit/index-START.html
index 4070d32767..0428ee56f8 100644
--- a/01 - JavaScript Drum Kit/index-START.html	
+++ b/01 - JavaScript Drum Kit/index-START.html	
@@ -58,7 +58,37 @@
   <audio data-key="76" src="sounds/tink.wav"></audio>
 
 <script>
+  const keys = document.querySelectorAll('.key');
 
+  window.addEventListener('keydown', playSound);
+
+  // add listener to every key for when css transitions end
+  keys.forEach(key => {
+    key.addEventListener('transitionend', removeTransform);
+  });
+
+
+  function playSound(e){
+    // get audio element that matches key pressed
+    const audio = document.querySelector(`audio[data-key="${e.keyCode}"]`);
+    const key = document.querySelector(`.key[data-key="${e.keyCode}"]`);
+
+    if(!audio) return;
+
+    // make sure playing from the start
+    audio.currentTime = 0;
+
+    // play sound
+    audio.play();
+
+    // add playing class
+    key.classList.add('playing'); // includes 'transform' css property
+  }
+
+  function removeTransform(e){
+    if(e.propertyName !== 'transform') return; // only listen for transform changes
+    this.classList.remove('playing');
+  }
 </script>
 
 
diff --git a/02 - JS and CSS Clock/index-START.html b/02 - JS and CSS Clock/index-START.html
index ee7eaefb1f..593d7be9a3 100644
--- a/02 - JS and CSS Clock/index-START.html	
+++ b/02 - JS and CSS Clock/index-START.html	
@@ -62,12 +62,39 @@
       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');
 
+    const setDate = () => {
+      const now = new Date();
+      const seconds = now.getSeconds();
+      const minutes = now.getMinutes();
+      const hours = now.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);
+
+    setDate();
 
   </script>
 </body>
diff --git a/04 - Array Cardio Day 1/index-START.html b/04 - Array Cardio Day 1/index-START.html
index eec0ffc31d..364d93e2be 100644
--- a/04 - Array Cardio Day 1/index-START.html	
+++ b/04 - Array Cardio Day 1/index-START.html	
@@ -31,17 +31,43 @@
 
     // Array.prototype.filter()
     // 1. Filter the list of inventors for those who were born in the 1500's
+    const fifteenhundreds = inventors.filter(function(inventor){
+      return (inventor.year > 1499 && inventor.year < 1600);
+    });
+    console.log(fifteenhundreds);
 
     // Array.prototype.map()
     // 2. Give us an array of the inventors' first and last names
+    const names = inventors.map(function(inventor){
+      return `${inventor.first} ${inventor.last}`;
+    });
+    console.log(names);
 
     // Array.prototype.sort()
     // 3. Sort the inventors by birthdate, oldest to youngest
+    const sorted = inventors.sort(function(a, b){
+      return a.year - b.year; 
+    });
+    console.log(sorted);
 
     // Array.prototype.reduce()
     // 4. How many years did all the inventors live?
+    let yearsLived = inventors.reduce(function(accumulator, current, index){
+      const inventor = {
+        name: `${current.first} ${current.last}`,
+        age: current.passed - current.year
+      };
+      accumulator.push(inventor);
+      return accumulator;
+    }, []);
+    console.log(yearsLived);
 
     // 5. Sort the inventors by years lived
+    yearsLived.sort(function(a, b){
+      return b.age - a.age;
+    });
+    console.log(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
@@ -49,10 +75,24 @@
 
     // 7. sort Exercise
     // Sort the people alphabetically by last name
+    people.sort(function(a, b){
+      return a.localeCompare(b);
+    });
+    console.log(people);
 
     // 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' ];
+    
+    let instances = data.reduce(function(accum, current, index){
+      if(accum[current]){
+        accum[current] += 1;
+      } else {
+        accum[current] = 1;
+      }
+      return accum;
+    }, {});
+    console.log(instances);
 
   </script>
 </body>