# Rotation

> Rotation is the daily music momentum chart: songs ranked by how fast they are gaining ground across the world's charts, measured over 15 platforms and 160+ markets, updated every day.

Rotation ranks songs by momentum, not size: a song sitting at number one everywhere has no momentum, while a song rising fast across many countries has a lot. Every ranked row publishes the signals behind it, so every position is checkable against the source chart it came from. The site also publishes numbered editorial pressings (curated records tied to cultural moments) and a free in-browser song key and BPM analyzer that uploads nothing.

## Core surfaces

- [The Rotation chart](https://rotation.today/): today's edition, updated daily
- [Trending](https://rotation.today/trending): the world view plus the full ranking
- [Song Key & BPM Analyzer](https://rotation.today/analyzer): free, in-browser, nothing uploads
- [Tap Tempo](https://rotation.today/analyzer/tap-tempo): tap out a BPM
- [Camelot Wheel](https://rotation.today/analyzer/camelot-wheel): harmonic mixing reference
- [Methodology](https://rotation.today/methodology): how the Rotation chart is calculated
- [Pressings](https://rotation.today/pressings): the numbered editorial archive

## Data

- Per-song pages at /song/[slug]: dated market history, sources, peaks, cultural context
- Dated edition permalinks at /[date]
- [Sitemap](https://rotation.today/sitemap.xml)