I find it interesting that a scientific study concluded that this song is the "most relaxing tune ever recorded" because it's not really my cup of tea. From the article cited below, "The song comprises of a sustaining rhythm that starts at 60 beats per minute and gradually slows to around 50. Thus, while listening to the song, your heartbeat automatically comes to match that beat. She even adds that it is necessary for the song to be eight minutes long because it takes about five minutes for entertainment to occur. The gaps between the notes have been chosen to create a feeling of euphoria and comfort." Why does this matter to Aikido training? Aikido is a very different martial art. It centers around being "balanced" and this balanced state begins with the mind. Our society teaches us to "get ahead" and this rat race mentality causes us to not only be out of balance but awards competitive and aggressive behaviors. Competition and aggression are forms of confrontation and thus confrontation is not the Way of Aikido.
In order for us to change and use the Way of Aikido we need a spend time living that way and training is how we do that. In order to do that we must leave the competitive confrontational world outside. Sensei used to say, "Cut off your head and leave it at the door." Sometimes that is easier said than done. People who have a hard time leaving it at the door might benefit from listening to this song (it's only 8 minutes long) before they come into the dojo so that they are calm and ready to train.
https://www.youtube.com/watch?v=CySNhHVAokQ&feature=youtu.be
Source: http://dailyhealthpost.com/according-to-scientists-this-is-the-most-relaxing-tune-ever-recorded/