Definition of an attunement
An attunement is a procedure where a person (or spirit guide) passes on a specific energy structure/signature to another persons energy body and/or energy centers (chakras). This enables the receiver to become a permanent channel for that specific energy.
The best known attunements are Reiki attunements. Reiki is an ancient healing art that was (re)discovered by a Japanese monk called Mikao Usui. He received attunement from spirit after he had fasted for about 3 weeks on a mountain. After a spiritual encounter he found that he could heal ailments just by placing his hands on a place of concern.
Usui's spiritual encounter had left an ”imprint” (attunement) in his spiritual bodies and chakras, which made him a permanent channel for the energy we today call Reiki (meaning universal life force).
Definition of an audio attunement
An audio attunement is a mp3 file with sound/music that has received the energystructure/signature of a specific attunement, in this case a Reiki attunement. When you play the file, the listener receives the attunement in much the same way as if it where passed on “traditionally”.