Voice
Lansky – Six Fantasies on a poem by Thomas Campion
Takemitsu - Vocalism Ai
Harvey - Mortuos Plango (an interview with him about the piece and his CMJ article about realising the piece at IRCAM )
Nono - La Fabricca illuminata
Berio - Thema (Omaggio a Joyce)
Karpen - Il nome (at ubuweb)
Crumb - Ancient voices of children
Ablinger - Voices and piano
These piece illustrate some of the ways composers have been using the human voice.
Articles looking at aspects of voice/music/sound
Kostelanetz Text-Sound Art.
Klein Voice and live electronics.
Palmer Some composer's opinions on solo vocal music
Bulut Theorising voice in performance.
Some other examples and sources, and a lecture by Johan Sundberg who studied the voice and how it works extensively: