Chopin's Revolutionary Étude- in Python reads a public domain encoding with mido, snaps it to a 1/24-beat Fraction grid, splits each hand into voices, writes an 808 that follows the left-hand bass into the same score, and synthesizes it all in numpy (Salamander piano, VSCO strings, a sine 808, an FDN hall). The score is then baked into PNG textures and three HLSL compute shaders draw the engraving, the kern terminal and the gold ball live. A checker verifies every note and every ball landing against the audio before each render.