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Belting out "Heavy Metal Lover," "Marry the Night," and "Born This Way," the New York City native, 25, worked the outdoor stage in a large black accessory that resembled a cage.
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As her performance progressed, the singer took off her topper to show off her fit figure in a black sequined bodysuit.
Later, Gaga helped NYC Mayor Michael Bloomberg lower the New Year's Eve ball wearing a Versace ensemble accessorized by a jeweled mask that covered her entire face.
