This comprehensive study of Thea Musgrave's Orfeo I is the basis for a lecture-recital performed on March 20, 1989, at the University of North Texas, as part of DMA dissertation requirements. It includes: brief bio-background of Musgrave and Orfeo; historical background of both the Orpheus legend and some landmark dramatic works based on it; general development of Musgrave's dramatic language and specific ways in which she uses it in this composition; analysis of the work; performance guide; and annotated appendix listing Musgrave's published and recorded chamber works which include flute. Orfeo I is a major work for flute and electronic tape comprised entirely of manipulated flute sounds. It was commissioned by the British Broadcasting Corporation for James Galway, who recorded the taped material and was the featured performer in the 1976 London premier. An alternate version, Orfeo II, with fifteen strings in place of electronic tape, was premiered by David Shostac in 1976 in Los Angeles, and conducted by the composer. Orfeo's form is programmatically designed, divided into six sections based on Musgrave's "Scenario"of the Orpheus myth. Characters are dramatically depicted through means of "motifs"; that of Orpheus in solo flute, and all others in tape sounds. Musgrave uses quotations from Gluck's opera, Orfeo ed Euridice and Stravinsky's ballet, Orpheus, as basic compositional models. Using her own harmonic language, she combines tonal and chromatic elements in a linear compositional style which ties flute and tape together. Through "controlled aleatory," the soloist is allowed to shape certain aspects of the work. Use of electronic tape places Orfeo I in the realm of intermedia. In addition, Musgrave offers a versatile range of performance possibilities, from highly dramatic (including lighting instructions, option of ballet choreography for solo male dancer, costuming, etc.) to a straight concert rendition.