How do I script a songs beat to a brick to?

Like if I were to play a song, as the beat hits a certain point the brick changes color

You can probably set up timing. Something like this:

local brick = script.Parent


function brickChange(time)
	wait (time)
	brick.BrickColor -- whatever the parameter is (brick color name whatever)
end


while true do
	brickChange() -- insert time inside there
end

this might not work, but you have to just tweak it. I don't think there is a way to detect bass in a song inside of Roblox.