The term 'ROCK'S ___ JOHN' is referring to the English singer, songwriter, pianist, and composer Elton John. Elton John has been one of the most successful musicians of all time, selling over 300 million records worldwide. He has been inducted into the Rock and Roll Hall of Fame and has won five Grammy Awards, an Academy Award, a Golden Globe Award, and a Tony Award. Elton John is known for his flamboyant stage performances and his iconic songs such as 'Your Song, ' 'Rocket Man, ' and 'Candle in the Wind.'