Twenty years ago last week, Billboard magazine introduced its Pop Songs chart, which measures radio airplay of songs only, as opposed to sales.  To celebrate the anniversary, the publication tallied which artists have scored the most hits on that particular chart, and it's crowned one queen... Rihanna .

In the 20 years that the Billboard Pop Songs chart has existed, Rihanna has scored more hits on it than any other artist.  She's appeared on the chart at total of 34 times, racked up 21 top-10 singles, and scored nine #1s.

Who did Rihanna beat for the crown?  Quite a few artists who've been around a lot longer than she has.  Here are the rest of the Billboard Pop Songs chart champions:

2. Pink
3. Britney Spears
4. Kelly Clarkson
5. Mariah Carey
6. Katy Perry
7. Usher
8. The Black Eyed Peas
9.  Janet Jackson
10. Madonna

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