Ichirou Mizuki's voice carries a children's song that sounds like it was written to comfort you specifically. The animation wraps around the melody so naturally you forget you're watching a music video at all. This is what happens when a master vocalist and a simple idea meet exactly the right format.
A music video made for the song Nan no Koreshiki Furoshikiman, sung by Ichirou Mizuki. The piece appeared on Minna no Uta, a program on NHK, and it runs as a single episode built around the track.