One may say that Jessie J is the best singer of our generation ("our generation" meaning, us, the kids who read articles about Jessie J). One may also say that this video of Jessie J singing with her mouth closed is only one of the doezens of reasons why the U.K. singer is the best of the best.
Seriously. How does she do it?
On "The Graham Norton Show," Jessie took on a few vocal runs, which are usually no big deal for her -- but this time, she demonstrated how she can do them as if she were in a box, with her cheeks puffed out to prime chimpmunk-ness.
You know who else is in a box, Jessie?