I agree with DavoidZX. It is a rhythm game and the patterns do repeat. Plus, at the start of each level theres a full 4 (or 8 depending on the level) bar period before the hexagon appears so you know what the beat is, AND the 3rd level already demonstrates that idea perfectly and shows how you beat is incorporated every 8th bar so you know whats coming up.
Anyway, yes, DavoidZX is right, because this is primarily a rhythm game, and having to depend on just your eyes and not your eyes AND your ears is probably not the best of things to do.