The Anthology Spectra Ex Machina brings together rare documents pertaining to so-called occult phenomena, most of them taken from little-known archives. In the course of three volumes, this series traces an audio history of parapsychology through the exploration of spiritualism and haunted houses (vol. 1); musician mediums (vol. 2); experiences of extrasensory perceptions (clairvoyance, psychokinesis, etc.) and electronic voice phenomena (vol. 3).

The link between music, sound and the paranormal is manifested in many different ways. Gerard van der Leeuw, the Dutch historian and philosopher, wrote "Music represents the great struggle of reaching the wholly other, which it can never express". Furthermore, "The effect of music on the emotions is so mysterious as to seem magical. There is no logical explanation why a particular combination of musical notes, whether in the form of a tune or of a simple chord, can affect the heart. Nothing in nature has perhaps so persistently resisted explanation", as said Derek Parker, the British journalist. Since music is arguably the most intangible of the arts and since the paranormal, in all its manifestations, continues to intrigue people, the placing of these two subjects together seems obvious. This second volume of musical and audio anomalies continues and expands upon the works initially reproduced in the latter. Rosemary Brown makes a welcome re-appearance, especially with a performance of Grübelei via Liszt, as well as the Caruso-inspired tenor Leo May making a repeat performance. Few people realize that both Anton LaVey and Aleister Crowley were quite fine musicians and Alex Sanders was also interested in music. The background music of Wagner's Tannhäuser used by the latter combines both pagan and Christian elements. So close your eyes and let the magic of sound take over!