Solution to #4: The Song

    The song snippet in the audio piece consists of three verses. Each verse's lyrics are taken from a different song:
      1. Mad Word, Gary Jules
      2. Zombie, The Cranberries
      3. Yellow, Coldplay
    In each set of lyrics, a word was intentionally left out. The missing words are hard, head, and yellow. The three words are a clue that points to the word "hardhat", which is the answer to this puzzle.

HARDHAT