The Unknown Music of Birds"The essence and the theoretical significance of the discovery of true animal (avian) music have been explained in detail and illustrated with numerous slowed down bird vocalizations in the author's book "The origin and the three realms of music - on the levels of pre-life, animal, and human existence", published in Hungarian in 1982 ... In making the choice of sound material for the record the author was guided not so much by the beauty of the vocalizations but by the beauty and the importance of the recognition of the Unknown..."