Ok, this is fun: The Vocal Ranges of the Greatest Singers*.
You really want to check out the site using your desktop: you don’t get to appreciate the site as well on your phone.
I found some of it surprising, though not all of it. Barry White is obviously well represented in the low end, and Mariah Carey is well represented in the high end. And while some singers don’t perform in a wide range, that’s no reflection on their singing ability (ahem, Aretha).
I also added an asterisk because people familiar with singers from the opera world would argue that all these pop singers are not truly the greatest.
But like I said, it’s just fun. Enjoy.