Katy Perry was serenaded by 14,000 fans during a gig in Belfast on Monday, as they sang Happy Birthday to the star.
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Katy Perry serenaded by fans
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Rihanna paid tribute to her British fans
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Supporters enjoy Music, Martinis and More
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Katie Holmes serenades Tom Cruise in a sexy stage performance
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Katy Perry climbs volcano
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Sting celebrates birthday
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You could party with a rock star on New year's Eve
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Pbc gives outstanding category to singers
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Katy Perry and John Mayer make their first public appearance as a couple
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Katy Perry wraps 'California Dreams' tour after 124 dates
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Katy Perry and Akon will be the musical guests on 'the VICTORIA'S SECRET FASHION SHOW'
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Justin Bieber joins Taylor Swift on stage
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Katy Perry has no regrets in life
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Katy Perry announces second leg of tour
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Katy Perry tries to be a 'better version' of herself
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X Factor hopefuls sing
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Katy Perry gets Sanskrit tattoo