Wadatsumi no Ki

Song: Wadatsumi no Ki
Artist: Chitose Hajime
Language: Japanese
Album: Hainumikaze
Released: 2002

"Studies have revealed that her particular style of singing, including aspects of traditional Amami-Ōshima music, has a relaxing effect that has been observed in electroencephalograms taken from the brains of people listening to her singing." Wikipedia

You be the judge of if this is true or not :)