A pie chart visualizes the distribution of Spotify's Top 50 songs from 2019 by genre. It fetches CSV data from a GitHub gist, uses `d3.rollup` to count songs per genre, and computes percentages for labels on each slice. The chart renders as SVG, using `d3.pie` and `d3.arc` for the sectors, a categorical color scheme, and includes a legend positioned to the right. A bold title and percentage labels are added directly on the arcs.