Katy Perry wrapped up 2013 with two very special private gigs, including one for TV self-help guru Dr. Phil Mcgraw's wife Robin. The pop star serenaded Dr. Phil's wife at her 60th birthday party after hitting the stage as a surprise guest. Oprah Winfrey and Vivica A. Fox reportedly attended the bash on 29 December (13) at McGraw's Beverly Hills mansion. Two days later, Perry was in Las Vegas for a private show at Caesars Palace's Fizz, where boyfriend John Mayer watched his lady from the wings.