Wealth may whisper, but Christina Aguilera, most certainly, does not.

Since Xtina's days as a child star of The Mickey Mouse Club, she's demonstrated unshakable resolution and confidence no empowerment seminar could teach. And at the root of her conviction is the type of voice that bends steel; a weapon of war that threatens each structure within its reach — get too close and you're as good as bowled-over.

Since the 1999 release of her self-titled debut LP, Aguilera's delivered one blindsiding performance after the next, dazzling audiences with tugboat bellows, sky-piercing screams and runs that would outpace a marathon racer. Whether she's tackling The National Anthem or "Lady Marmalade," she's proven over the years that sticking to the melody has simply never been of great concern. With five Grammy Awards to her name and worldwide sales that have topped 50-million, it's safe to say that strategy has not yet done her any sort of disservice.

Above, we've collected some Xtina's most signature sets, from the excitingly unhinged rendition of "It's a Man's Man's Man's World" at the 2007 Grammy Awards to the big band-backed "Ain't No Other Man" at the MTV Video Music Awards one year earlier. Watch her move mountains and make waves, and if your favorite performance didn't wind up featured, be sure to share it in the comments.

Look Back at a Collection of Christina Aguilera's Wildest Looks: