2000 — John Cassidy, "They Are The World", New Yorker, 9 October 2000:
Helms, whose enthusiasm for mononymic rock stars has hitherto passed unremarked, was so overcome by Bono's presentation that tears ran down his cheeks, […]
2002 — Jan Freeman, "Call him Saddam", Boston Globe, 17 November 2002:
A few newspapers use courtesy titles - Mr. Black, Mr. Hussein - except when they're stymied by a mononymic celeb like Cher or Eminem.
In America our fascination with knighthood can be seen in colloquial titles bestowed upon celebrities like Elvis, the King of Rock ‘n’ Roll, Michael Jackson, and the naming of mononymic star, Prince, although not in an official and REAL ROYAL WAY!