An excerpt from Chapter 3 of A Psychic Study of the Music of the Spheres by D. Scott Rogo Order the book here.

As with any case of psychic phenomena the first important consideration is whether the phenomenon can be explained normally before evaluating its paranormal qualities. In cases of deathbed music the problem is easier, since collective cases exist. But what of those subjective experiences of the dying, and of persons in normal states or during the out of the body experience? These are much harder groups of experiences to analyze. Historically, such cases have never been eagerly accepted as genuine by parapsychologists. Frank Podmore, among the first scholars to work with the Society for Psychical Research (founded in 1882), was one of the three authors of Phantasms of the Living. His attitude about psychic music can be found in his volume Modern Spiritualism: "In dealing with clairandience, the hearing of voices, music, and the like, we do not find any such wealth of material to assist our analysis; nor indeed does the subject lend itself so readily to systematic investigation. But there is no reason to doubt that the phenomena have, physiologically, the same origin as the visions which we have just been considering... simply the result of the exaggerated activity of lower cerebral strata, released for the time from the repressive control habitually exercised by the higher centres. " René Sudre, the French psychist, has gone a step further and described such cases as perhaps due to "pathological hallucination" (Treatise on Parapsychology, London: Allen & Unwin, 1960). No matter what one thinks of the above explanation, the hallucination theory must be considered and not merely brushed aside. In the previous chapter I quoted Dr. Jule Eisenbud who, tongue in cheek, remarked that the descriptions of many of the percipients seemed like the reports of patients having electrodes connected to the hypothalamus and cerebral cortex. What really must be discussed is, firstly, can there be found a neurological basis for some type of musical phenomenon? Secondly, does it seem similar to our data? And lastly, can it, in fact, explain our data? To the first question we must answer yes. A neurological basis for hearing music was discovered by Dr. Wilder Penfield, director of the Montreal Neurological Institute. In 1955 Penfield reported on his experiments placing electrodes on the temporal lobe cortex. To quote from his report: "The patient might exclaim in sudden surprise that he heard music, or that he heard a well known person speaking, or that he saw something he had seen before, or that he was himself taking part in a former experience in which he was himself an actor. "A young woman heard music when a certain point in the superior surfaces of the temporal cortex was stimulated. She said she heard an orchestra playing a song. The same song was forced into her consciousness over and over again by restimulation of the same spot. It progressed from verse to chorus at what must have been the tempo of the orchestra when she had heard it playing thus. She was quite sure each time that someone had turned on a gramophone in the operating room. "There were many other examples of hearing music, but always the patient heard a singing voice, or a piano, or an organ, or an orchestra, and sometimes he seemed to be present in the room or in church where he had heard it. What he heard in experience was a single occasion recalled to him with a vividness that was much greater than anything he could summon voluntarily by efforts of will." Could this be the source of the enigmatic NAD [paranormal music]? Actually, Penfield's discovery has little in common with transcendental music. These differences can be categorized point by point. One of Penfield's subjects felt sure that someone had turned on a radio or phonograph. Rarely in our cases of subjectively heard music did any of the percipients have the slightest doubt that they were hearing something that was beyond normal music. On rare occasions, at the onset of the experience, such a notion was pondered briefly, but immediately rejected...

A Psychic Study of the Music of the Spheres Table of Contents Foreword by Raymond Bayless Preface Part I Chapter 1 – Introduction Chapter 2 Psychic Music: Its Various Manifestations Part II An Index of Cases Introduction Type I NAD in Normal States of Consciousness Type II Out of the Body Experiences Discussion: The NAD Experience Paranormal or Mystical? An Attempt at Verifying the NAD Experience Type III Cases Related to Death Part III Chapter 3  Some Considerations of the Phenomenon Chapter 4 Psychic Music: Sense Perception or Psychic Perception? Chapter 5 Psychic Music: Some Unusual Manifestations Chapter 6 The Music of "The Next World"? Chapter 7 The Final Question Conclusions: NAD, Death, and the Ecstasy of Experience Appendix A Dubious and Pseudo NAD Cases Appendix B The Western Tradition of Astral Projection Appendix C Ancient Doctrines of NAD Combined Index of Cases Acknowledgments Bibliography