First of all: for anyone who hasn't played this game, PLEASE DON'T READ THIS COMMENT! It explains how one of the puzzle works, and I think you should at least try to work it out for yourself first before reading!
I assume you're talking about this puzzle:
Sorry you got stuck here, given it's my personal favourite puzzle of the 3! It's a code-cracker where each direction corresponds with a musical note (stepping on the buttons tells you which corresponds with which). When you approach the path, a melody plays which tells you which path to take. For example, if D corresponds with up and G corresponds with right, and the melody plays 'D G G D', it's telling you the correct path is 'up, right, right, up'. Hope this helps!