I have often listened to musical interpretations of Gurdjieff's compositions. My main source has been Keith Jarret's 'Sacred Hymns of G.I. Gurdjieff' which is wonderful piano work. A second, though less preferable source, is 'Gurdjieff & de Hartmann - Piano Works'.
However, I recently came across and purchased 'Gurdjieff; Tsabropoulos - Chants, Hymns and Dances' which combines compositions from both Gurdjieff and Tsabropoulos (a Greek composer), with piano and cello - and this is the most beautiful version I have found so far. Enchanting, relaxing, etheral. Warmly recommended - and another great product from the ECM label.