The Megatronix SC620 Six Tone Car Alarm is also fun to watch: https://www.youtube.com/watch?v=xXYc0gtOswQ&list=PLn67ccdhCs...
As well as the a cappella Starships (Nicki Minaj cover) by Mike Tompkins which has a mind-blowing breakdown of how he built up the composition from different vocals at the end: https://youtu.be/vDqHpWY1UD4?t=209