# Rhythm and polyrhythm

Rhythm and pitch are closer than they seem. A drum played four times a second is a rhythm. Speed it up to a hundred times a second and you hear a low note. In the same way, three beats against two, a polyrhythm, becomes a fifth when it is sped up, because the fifth is the ratio 3:2. Another link with mathematics is in how strokes are spread round a cycle: placing them as evenly as possible gives many of the bell patterns of West Africa and Cuba.

Connects to:
- [Clock arithmetic](https://mapideas.org/i/mu_clock)
- [Rāga and śruti](https://mapideas.org/i/mu_raga)
- [West African timelines](https://mapideas.org/i/mu_africa)
- [Ratios](https://mapideas.org/i/mu_ratio)
- [Notation](https://mapideas.org/i/mu_notation)

Sources:
- [Wikipedia: Euclidean rhythm](https://en.wikipedia.org/wiki/Euclidean_rhythm)
- [What is music? Module 8, rhythm, time and cycles and Lab 8a](https://sofiagallego.com/what-is-music/)

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