Found this a little bit ago by chance at the bottom of the Hacker News front page. Very, very cool.
“Bass wobble - Notes based on smoothed out NASDAQ overall trading volumes. Wobble rate based on current volatility of the NASDAQ overall trading.
Melody - Apple performance vs NASDAQ100 index.
Basic beat - Static.
Hi-hat - Triggered when the overal nasdaq trading volume is above 2 minute rolling average."