Lady Gaga is quietly mourning David Bowie and will pay tribute to him at the Grammy Awards, sources exclusively tell Page Six.

“There’s been discussions about a Bowie tribute, but nothing is confirmed yet,” said a source close to Gaga.

Meanwhile, songwriter Linda Perry was forced to apologize after fuming over Gaga’s Oscar nomination for her song with Diane Warren, “Til It Happens to You.”

Perry tweeted Monday of Gaga’s contribution to the song for campus rape documentary “The Hunting Ground.”

“I have Diane’s original demo . . . the only line that has been changed [is] ‘Till you’re at the end, the end of the rope’ . . . so sure Gaga [possibly] ‘rewrote’ a line.”

She added: “If she gave Gaga writing credit it would ensure the support this song needed and deserved. And Gaga knows her power . . . I credit Diane for writing this song, it is her experience her pain her words.”

But Warren responded: “The song is the result of a special collaboration between myself and Lady Gaga.”

Later on Monday, Perry — who’s penned or produced tunes for Gwen Stefani, Christina Aguilera and Celine Dion — backpedaled:

“My sincere apologies. I made a mistake to comment. I wasn’t in the room when [the song] was being written . . . I wish the focus to remain on the great importance of the song and the message of the film.”