Harp column and joystick: what they have in common
- Step 1. Harp column — is part of — Harp. It holds the tension of the strings.
- Step 2. Harp — evolved into — Guitar. Plucked instruments.
- Step 3. Guitar — evolved into — Electric guitar. Electrification.
- Step 4. Electric guitar — has part — Potentiometer. The volume and tone knobs on an electric guitar are potentiometers.
- Step 5. Potentiometer — is used in — Joystick. Position is read with potentiometers.