Physics demo showing how standing waves can be set up on a string that is vibrating from one side where the other side of the string is tied down. Once we know the fundamental frequency, we can see additional harmonics if we go up in multiples of that fundamental frequency. This in a really important idea particularly for music whether you are talking about a stringed instrument like a guitar or aerophones like a flute | Fadhel Mahdi

Sympathetic Resonance: mechanical energy is transmitted from one vibrating tuning fork to the other via sound- as revealed by a wood bead on a string. A beautiful example of resonance phenomena where tiny periodic accelerations (such as sound waves) can produce much larger scale accelerations and displacements if the frequency matches the natural frequency (or an overtone) of the structure. This set of tuning forks are manufactured to vibrate at the same frequency and are mounted on resonating c