Have a fussy baby? Researchers believe they have the solution: a simple lullaby specifically designed to make babies happy. Though it's a simple tune, the process behind "The Happy Song" was actually quite complicated, per Time. The song is the result of plenty of research into infant musical tastes, which revealed infants would likely respond best to an upbeat song in a major key that was simple and repetitive, but also used various musical devices for an element of surprise, child development expert Caspar Addyman writes at the Conversation.
Once a list of requirements was agreed upon, Addyman and musical psychologist Lauren Stewart enlisted Grammy winner Imogen Heap, who has an 18-month-old daughter, to create four test melodies.