From political doomsday ditties to futuristic imaginings of the apocalypse, musicians have long been penning songs for the end of days. With yet another doomsday forecast targeting Dec. 21 as the big kick-off date, shall we, in the immortal words of Britney Spears, "dance 'til the world ends"? Whether you'd prefer to brood about The End with the Doors, recklessly sip Jack with Ke$ha, or slow dance your way to impending doom with Aerosmith, here is The Week's first (and perhaps last) playlist of classic songs about the end of the world: