To the toccata portion of Bach's "Toccata and fugue in D minor," we watch a play of sorts. Blue smoke forms a background; a grid of black lines is the foreground. Behind the lines, a triangle appears, then patterns of multiple triangles. Their movements reflect the music's rhythm. Behind the barrier of the black lines, the triangle moves, jumps, and takes on multiple shapes. In contrast with the blue and the black, the triangles are warm: orange, red, yellow. The black lines bend, swirl into a vortex, then disappear. The triangle pulsates and a set of many of them rises.

• Animation