- Siren: https://makecode.microbit.org/_DuvTURDrsc3c
- Hardware: Wukong breakout for microbit https://www.elecfreaks.com/learn-en/microbitExtensionModule/wukong.html
- Frequencies from below: https://bbs.21ic.com/icview-1669-1-1.html https://en.wikipedia.org/wiki/Piano_key_frequencies