Other highlights of Trainor's Hot 100 coronation: "Bass" is the second debut No. 1 by a lead female artist this year, following Iggy Azalea's seven-week reign with "Fancy," featuring Charli XCX. The last year in which two maiden entries by women in lead roles ruled the Hot 100? 2008, when Leona Lewis ("Bleeding Love") and Katy Perry ("I Kissed a Girl") each dominated on their first tries.