The only thing that can make this baby stop crying is Katy Perry [1] — seriously! We can't stop smiling over this adorable little girl who does not want to be in her car seat . . . until Mom cranks up the radio. Who'd have known that the pop star's hit "Dark Horse" doubles as a magical lullaby?! We're very curious as to whether or not the Katy Perry effect is universal to all crying infants.