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Elton John and Lady Gaga are reportedly planning a Grammy night duet on Sunday.

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It is not known what the colorful couple will be performing together, but website insists the Grammy get together will be "the coolest collaboration ever".

A source says, "Elton and Lady Gaga on the same stage is sure to create fireworks, it could be one of the most memorable Grammy performances of all time."

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It won't be the first time the "Rocket Man" has performed a headline-grabbing duet at the Grammys. In 2001, he shared the stage with rapper Eminem.

Other artists set to perform at the 52nd annual Grammy Awards include Pink, Beyonce, Black Eyed Peas and Taylor Swift.

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