Rockstar Rod Stewart has cancelled his Cincinnati concert amid fears for his health, admitting he underwent an unforeseen medical procedure earlier this week. Rod Stewart. Rod Stewart during the Utah show. Pic: Holly Green/FacebookHe was diagnosed with an upper respiratory tract infection last month, and required oxygen backstage during his tour. However, there has also been some happy news in Rod Stewart’s life as his daughter Ruby recently gave birth to her second child, a little boy named Levi who is the sixth grandchild for the Maggie May hitmaker.