HIP-hop mogul Andre Harrell recently survived quadruple bypass heart surgery, and his relieved friends celebrated with him the other night at the Upper East Side townhouse of Warner Music chairman Lyor Cohen, where guests included Mary J. Blige, Jay-Z, Chris Rock, Andre Balazs, Jason Binn, Jellybean and Caroline Benitez, Harrell's son Gianni, 14, who plays point guard for the Horace Mann basketball team, and Gianni's mom, Wendy. "Andre said he was happy to be alive and happy to have all of them as his friends," said one guest, "particularly Sean Combs, who was there at the hospital when he was put under for surgery, and there when he came to in the recovery room."