Making rhythm games similar to tap tap revenge possible with GameObjects?

Hi all. Once again im back with Unity after a long time with C# o.O And now im trying to recreate a game I made using Microsoft Visual C# Express... A game similar to tap tap revenge. Aparently, I am using GameObjects to represent those "notes" that appears and so I am trying to find a way to synchronise every instant of JavaScript class with a "note" which is the GameObject so that i can add extra data binded together with the GameObject itself, such as the actual position of the "note/tapper" to know if this "note" is behind or after that "note" to avoid that cheapo rhythm game glitch where one "tap" can remove two "notes" at the same time. Currently I have four prefabs of 4 different coloured "notes" that requires the keys "U","I","O" and "P" to "tap" the "notes". Is creating a GameObject variable inside a class and attaching the prefab to every instance of the note class possible? Also, is running a foreach loop through each of the 4 arrays that contains "notes" at different positions to update the infomation and apply it to the GameObject possible? If possible, how should I do it to prevent the least amount of lag to occur? Because I am not a performance expert so I am seriously getting much lag from the way I code in unity...