It may be called Back To Basics: Live And Down Under, but that doesn’t mean Christina Aguilera has forgotten how to put on a blowout of a concert. The iconic diva set up a full carnival for this live go-round, with acrobats, stilt-walkers and head-spinning dance moves sharing her stage. But it’s her killer catalog of songs, from “Genie in a Bottle” and “Ain’t No Other Man” to “Hurt” and the showstopping “Beautiful,” that truly brought the house to its feet, all sung by one of the most inimitable voices in modern pop music.