What? You don’t have a Led Zeppelin song in your repertoire? Well, isn’t it high time you got one? The answer is, maybe. For one thing, this arrangement requires an extra soloist or two, making it better suited to a chorus than quartet. Also, many of the tricky instrumental effects are reproduced vocally, making this piece very . . . not easy. But if your group can pull it off, your audiences are bound to go bonkers!