Do any of you play any stringed musical instruments? If so, then you’re probably familiar with the term ‘harmonic’, which is just a kind of special sound created by playing in a specific way. On the violin, you need to gently press the string with a finger whilst bowing, such that you are able to feel the vibrations of the string beneath your finger. The sound created is almost flute-like and has a silvery, hollow quality to it. However, this sound can only be created at certain intervals along the string, ½, ⅓, ¼, etc. Anywhere else on the string, it sort of sounds like metal wires being dragged down a blackboard. Yeah, don’t try it. So why is this weird sound only produced at ‘nice’ fractions of the string? And how does a stringed instrument work anyway?