Elon Musk has launched you into space. You're heading to Mars via a one-man space craft. The journey takes six months. On day three your trusty space craft, Pegasus, suffers a catastrophic failure. To stay alive you must dump massive amounts of data. Adding insult to injury only two of your play lists survived the equipment breakdown but one must be deleted. Are you keeping Bon Iver or Bon Jovi. Which band gets jettison out the metaphorical airlock?