This scatter plot maps music tracks by their danceability and energy levels, with each point’s size encoding popularity and color representing genre. A sidebar of checkboxes lets users toggle which genres appear, filtering the visualization to compare overlapping categories. Built with React and D3 v7, the chart uses `scaleLinear` for axes, `scaleOrdinal` with `schemeCategory10` for genre colors, and D3’s `join` operator to update SVG circles and legends as selections change.