I know how to use CC Cylinder, which I'm using to create a rotating loop of piano keys... as the keyboard rotates, different hands enter and exit the view playing it... but what I would like is to have some light rays animated to the music going through the center of the cylinder. I already can animate the rays. I just need help getting the rays to go through the eye of the cylinder. Is that an obscure setting somewhere in the cylinder effect, or is it going to take some complicated masking?
Could be as trivial as using a duplicate of your existing comp in a parent comp and applying the effect. You know, pre-composing. Of course there's always the chance you may need to draw a matching white circle somewhere to get really intense rays that "pop", but it's hard to judge on that without seeing at least a screenshot of your work.