a - London's New Year's Day Parade has evolved into one of the world's great street spectaculars with up to 10,000 performers from across continents, hundreds of thousands of spectators, and a 'live' TV audience of several hundred million. - London, United Kingdom - Friday 1st January 2016 (1 Picture)
Photo credit: Ana Maria Wiggins
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Perry appeared on James Corden's 'The Late Late Show' on Monday and addressed her long-standing rivalry with Swift.