On the anniversary of Michael Jackson’s death, his brothers Tito and Jackie Jackson threw a dinner for 25 on the Upper East Side on Monday before heading to the Apollo Theater to rehearse for their sold-out gig tomorrow with brothers Marlon and Jermaine. “Most of the guests were band members who will preform at the Apollo,” said a spy who spotted the music legends at Italian restaurant Canaletto. “They a had big, glorious dinner before heading to Harlem to rehearse for the sold-out performance.” Downtown, Andre Harrell and Richie Akiva hosted a fourth annual “Remember the Time Michael Jackson Tribute Party” at the Darby. DJ Cassidy spun the King of Pop’s hits, and guests included Russell Simmons.