Oh, the so-called lost "album that although 1973 (before Phaedra" was recorded) only published in 1986. The reason why the album for many years was forgotten, I do not know, so I can only speculate. While listening to the four tracks I can well imagine that Tangerine Dream were then surprised and unsettled as Green Desert, "White Clouds", Astral Voyager "and Indian Summer" very melodic and compact sounded and were driven by sequencer bass. Perhaps the band had fear of publication, because the shots were so far ahead of their time (only in the second half of the seventies, the Tangs should sound like) and had scared because of their melodic fans. In fact, Phaedra was "the logical successor to breath" and placed in and of itself constitutes a turning point for the Tangs.
Nevertheless: for TD fans is Green Desert ", the Cyclone" love or Force Majeure ", indispensable emerged albeit five years earlier.
In other words, with this album Tangerine Dream have already envisaged in 1973, to give 3 years later, Jean-Michel Jarre Oxygene with "a mega seller made (albeit the level at TD was more significant).