G. I. Gurdjieff travelled for many years through Central Asia and the Middle East collecting melodies and ritual dances, which his friend and pupil Thomas de Hartmann wrote down and arranged as piano pieces.
Music for the Piano Volume IV : Hymns from a Great Temple, and other Selected Works
Georges Ivanovich Gurdjieff, Thomas de Hartmann
book
Music for the Piano Volume II : Music of the Sayyids and the Dervishes
Georges Ivanovich Gurdjieff, Thomas de Hartmann
book
Music for the Piano Volume III : Hymns, Prayers, and Rituals
Georges Ivanovich Gurdjieff, Thomas de Hartmann
book