# Vibration and pitch

Every sound starts with something moving back and forth: a violin string, a clarinet reed, the air inside a flute, your own vocal folds. The number of times it moves back and forth each second is its frequency, measured in hertz (Hz). We hear frequency as pitch. The A that orchestras tune to moves 440 times a second, and the A an octave below moves 220 times. When you pluck a string the sound gets quieter as it fades, but the pitch stays the same, because the string keeps the same rhythm while its movement gets smaller.

Connects to:
- [Sound in the air](https://mapideas.org/i/mu_wave)
- [Strings and pipes](https://mapideas.org/i/mu_string)
- [Music](https://mapideas.org/i/music)

Sources:
- [What is music? Module 1, the oscillator and Lab 1](https://sofiagallego.com/what-is-music/)

Source: https://mapideas.org/i/mu_vibration · open on the map: https://mapideas.org/#mu_vibration