Eva Baker posted this video on YouTube
of a fussy baby abruptly brought to wonder and joy at the sound of Katy Perry's Prism single, Dark Horse.
Just look at the baby's reaction when Dark Horse starts playing.
That is the "this is my jam" face to end all "this is my jam" faces. That adorable expression is the look of someone whose every worry has just disappeared entirely.
Then Katy's verse kicks in and the baby let's out an audible, "ohhh...."
Oh, and Katy Perry totally saw the video and tweeted about it.
Watch the video if you like adorable things and/or smiling forever.