I suspect that what you may be experiencing is a state of "altered consciousness" -- some people/cultures arrive at it through drugs, others use exercises like yoga, or chanting or drumbeats (especially shamans), and some people use music. The phrases "getting in the groove" or "spacing out" are probably apt descriptions of this sort of phenomena. Oh God, I could be a pop psychologist if I had the right buzz words. ?!?!?! It is a pleasurable state.