Aleksi Tuomela shows an easy way to create a spectrogram music visualizer in Blender.

Check out this tutorial from Aleksi Tuomela, which covers making a spectrogram music visualizer in Blender using Geometry Nodes and other tricks. Aleksi uses an online tool that will generate a spectrogram from an audio file.

Toumela then uses that generated image in Blender with Geometry Nodes to make a rolling grid extrusion based on the visualized music animation.

If you are diving into GeoNodes in Blender, Remington Markham (SouthernShotty) had a tutorial that walks through what each node does, explaining how they each might be used.