Carrie Underwood and Tony Bennett have booked 'Blue Bloods' guest roles.

The Grammy winners will play themselves on the season premiere of the CBS police drama.

Look for the duo to perform at a fundraiser that Frank Reagan (Tom Selleck) and Erin Reagan-Boyle (Bridget Moynahan) are attending in the new mayor's honor. Bennett and Underwood will sing 'It Had To Be You.'

"Having musical legend Tony Bennett and the hugely talented country music star Carrie Underwood perform on our show is a true gift. The talent that they bring together is amazing," Leonard Goldberg, 'Blue Bloods' executive producer, said in a statement. "We're looking forward to an exciting second season premiere with a story that is certain to provoke debate, and are thrilled that Tony and Carrie can be a part of it."

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