It's not often that a fully planned and perfectly executed performance feels so very nonsensical, but that's exactly what happened when Sia came to 'Late Night with Seth Meyers' with a very special guest, Lena Dunham.

Sia was definitely onstage for her entire performance, but facedown on a bunk bed while Dunham danced wildly around to the dulcet tones of "Chandelier." Totally random, perhaps brilliant, and compulsively watchable, this is how you do a "special guest."