Orpheus (north east Danube valley) and even describes him wandering into Hyperborea and Tanais (ancient Greek city in the Don river delta) due to his grief. The story of Eurydice may actually be a late addition to the Orpheus myths. In particular, the name "Eurudike" ("she whose justice extends widely") recalls cult-titles attached to Persephone. According to the theories of poet Robert Graves, the myth may have been derived from another Orpheus legend, in which he travels to Tartarus and charms the goddess Hecate. The myth theme of not looking back, an essential precaution in Jason's raising of chthonic Brimo Hekate
The Mask of Orpheus with the Orpheus myth decaying. "The Mask of Orpheus", in addition to vocal and orchestral music, contains a significant amount of electronic music, (which was precisely composed by Birtwistle, and realized on his behalf by Barry Anderson). Each act has its own electronic "aura", which goes on continuously, sometimes prominently, sometimes inaudibly; the voice of Apollo is heard on several occasions as an electronic sound "speaking" in an invented language. These electronic sounds were made by Anderson in Paris at IRCAM. There are also six purely electronic interludes created by computer manipulation of harp sounds. Jocelyn Herbert was commissioned to