Music for Nine and Computer is a musical composition for an ensemble consisting of flute, Bb clarinet, Bb trumpet, marimba, drum set, piano, violin, cello, contrabass, and computer-controlled sound processor. The instruments are electronically amplified and have their sound processed by a digital signal processing module controlled by a Macintosh computer. The sound processing techniques include pitch shifting, comb filtering, and extreme changes of reverberation and room characteristics. The electronic sound processing is tightly coordinated with the rhythm and dynamics of the piece. The dissertation essay looks at Music for Nine and Computer in terms of its particular musical language and the ways in which the electronic processing echoes and amplifies that language. A variety of sources and influences are discussed in an attempt to set the musical context of the composition, particularly in terms of jazz and other types of American vernacular music. Specific local areas of the composition are analyzed in terms of their melodic, harmonic and rhythmic content. This local content is related to the overall structural organization of the piece and the integration of the electronic processing.