Singing is more complicated than simply opening one's mouth and pushing air through the vocal cords.
There's a deep psychological component as well, which is why Toby Twining has spent his career experimenting with the range of sounds the human voice can make.
"Vocal music is like holding onto a live electrical wire," said Twining in a telephone interview last week. "The human voice is more vulnerable in an emotional way and even a physical way because it involves a person."
Twining, whose Toby Twining Music, a six-voice ensemble, will perform next weekend as part of the New Music New College series, grew up in Texas with family roots in country-swing and gospel music, but when he went to college at the University of Illinois as a music major, he joined the madrigal singers.
"I'd been singing all my life but didn't realize I could do that kind of work, that I could sing Renaissance music," he said. "That started to get my feet wet with a more evolved kind of composition that uses the voice."
He also was working as a dance accompanist, playing the piano for the dance department, which encouraged him to use his voice. That, combined with a growing interest in world music, led him to yodeling and overtone music.
An invitation by composer William Brooks to sing in a program of works by 20th-century composers, including John Cage and Karl Heinz Stockhausen "opened my eyes to this sense of vast, unexplored territory for vocal ensemble, and also opened my eyes to the ability to do it," he said. "I had a vocal instrument that I didn't realize I could use in a professional way."
In 1991 he formed Toby Twining Music, now four male and two female voices and a cello. In addition to Twining, the musicians include Eric Brenner, Eileen Clark, Avery Griffin, Steven Hrycelak and Malina Rauschenfels, who sings and plays the cello.
What they do is neither easy to explain nor to perform.
"One of the challenges is you need musicians who are trained in European and classical pedagogy, in the belle canto tradition, which is mostly used to create opera singers," he said. "Very often people trained that way won't want to explore different techniques. The singers who tend to work with me have developed their belle canto technique, but they also have in their background singing rock 'n roll or jazz, so it's not difficult for them to switch into other types of vocal work."
Despite the pitch limitations on the human voice, Twining considers it the most flexible musical instrument.
"It has such a vast array of sounds and nuances of sounds. There's an enormous palette of colors to work with, and it's very challenging to orchestrate with such a vast array of colors."
The program for next Saturday includes music from Twining's score for the play "Eurydice" by Sarah Ruhl, selections from the recent recording, "Shaman," and two songs from a project now being developed of settings from Herman Hesse's book, "Wandering," in English and German.
The book was introduced to Twining by his friend, the pianist Margaret Leng Tan.
"It's almost a children's book," said Twining. "I think he wrote it between the wars, wandering around the Swiss-Italian Alps by himself, writing short, philosophical essays inspired by the various places he stopped. He also wrote poems and was doing watercolors. It's very simple and childlike, and was one of Margaret's favorite books when she was a girl."
The ensemble is singing James Wright's translation of two poems from the book, "Magic Colors" and "Walk at Night."
"They're really fun," said Twining. "They combine German lieder with progressive a cappella."