A very light form of trance characterized by heaviness of the limbs, apathy, feelings of detachment, and light visionary experiences with the eyes closed. It can be induced by drumming, chanting, dancing, and other known methods for trance induction.
Sleep-learning (also known as sleep-teaching or hypnopædia) attempts to convey information to a sleeping person, typically by playing a sound recording to them while they sleep.
The art of teaching someone a lesson in their sleep so that they can remember it when asked.
For me, hypnopaedia and Music are very much alike. For example, whenever I fall asleep listening to music, the next morning when I wake up, I will have the song stuck in my head. I will be singing it aloud (non intentionally,) but when someone asks me what song it is, or what the lyrics are, I have no clue.