The human voice is the most communicative musical instrument of all. It is interesting to note that while modern voice synthesis techniques go back much farther than those for other musical instruments , it is one of the instruments that is farthest from reaching parity between the synthetic and natural versions. This seems to be primarily due to the complex fluidity of control involved and to the incompleteness of the physio-acoustic models used. Nevertheless, excellent singing voice quality based on a digital waveguide model has been achieved for isolated phrases by Perry Cook [12,13]. Since voice is in a class by itself relative to other musical instruments, and since it is addressed elsewhere in this special issue , it will not be discussed further here.