I was also fascinated by the idea and thought to myself to build something similar.

I already got LEDs, except the wire and tubes. My LEDs are already in tubes (one can choose on Aliexpress).

I would take an esp32 and run WLED on it. LedFX also works with it, to illuminate according to sound. Not that fancy like addressing each pixel with your own rules, but nice enough to watch it for a while.

Without the pi but with the esp32 it’s about 70€ for the parts.