Tom DePlonty and I recently made an album called The Detail of Little Events. In it we used recordings of voice in the public domain from the web, and I found the use of natural voice to create instruments in my software synthesis units (Iris, stuff like that), that I made an album, Sol. La. Fa., which uses voice as the basis for the entire set. There are twelve shorter pieces on the CD, and some are taken from the Sacred Harp tradition (Windham), some from just folk tunes (Old Granny Hare), from hymnals (Ancient of Days), and some just from my voice (Het uitzicht vanaf de berg).
I was going to call the album Fasola, but isn't that already taken?