In case you were temporarily rendered blind by loose wig fibers and had to turn in early, Sia stopped by The Voice finale last night to sing her most recent hit, “Cheap Thrills.†Joined by a trio of dancers including her stalwart muse Maddie Ziegler, Sia celebrated the inexpensive delights of hitting the club with your lover, minus the money you paid for dance lessons to learn the Harlequin Mime Human Centipede, or whatever you would call that one move.