That's one part of it but there are numerous, cheap, COTS audio to RGBA drivers with zillions of music-following modes that work well enough. The hardest part

That's one part of it but there are numerous, cheap, COTS audio to RGBA drivers with zillions of music-following modes that work well enough. The hardest part IMO is distributing it to a lot of LEDs over a large area. It usually involves finding the single serial maximum power length, cutting a bit before that, and SPI multiplexer(s) like SP901E, and strategically distributing right-sized power supplies. SPI amplifiers are also sometimes needed on long runs that skip across areas.