Preview: Chanticleer's a cappella singers make beautiful music without a conductor

Anyone who has sung in a choir or vocal ensemble can attest to how narrow a path singing a cappella can be. With no piano, organ, orchestra, band or other instruments to keep you in tune and together, each person has more responsibility for the performance.

That means that the 12 singers of Chanticleer might be the most conscientious musicians in the world. Not only does the Grammy Award-winning male choir sing a capella all over the world, it does so without a conductor.

"Because they cannot lean on a conductor, the singers must take total ownership," says Jace Wittig, a singer in the San Francisco-based group. But Mr. Wittig has the title of music director. Isn't that just another name for conductor, as it is for most ensembles and orchestras?

"The music director functions more as a facilitator of rehearsal," says Wittig. "I lead the rehearsals and guide the ensemble through a piece, but I try to get out of the way as quickly as I can. The group functions most efficiently when the music director stops conducting, because the job of the [singers] is to connect directly with each other as opposed to channeling their energy through a conductor."

Part of the reason this structure works is that the music director has always had a long tenure singing with the group before moving up. Even its founder, the late Louis Botto, sang and led the group that debuted in 1978. This is unlike orchestras in which maestros are almost always chosen from outside the organizations. "Chanticleer has thus far promoted from within because what we do is rather unlike most choirs," says Mr. Wittig. "It's beneficial to us to have someone who understands what it's like 'on the inside.' "

But just as important is that the performers are extraordinarily committed. "Each singer has to understand not only his individual part, but also the poetry, the structure of the musical writing, the inspirations of the composer, the context of the piece within the program. In essence, each singer must have the knowledge of a conductor. It's very important that we come to an agreement about virtually everything in a piece of music,"

And that gumption is needed since the repertoire of Chanticleer, named after the singing rooster of Chaucer's "Canterbury Tales," spans a millennium: from chant to Renaissance vocal polyphony, from Romantic choral standards to spirituals, jazz and new music. Chanticleer will sing from these periods when it performs at Shadyside Presbyterian Church Sunday. The program includes new works by composers Chen Yi, Michael McGlynn and Mason Bates and well-known music of Vaughan Williams, Barber, Gesualdo and more.

"The variety of repertoire we perform is one of the great joys of being in Chanticleer," says Mr. Wittig. "We perform well over 100 concerts each season, and the variety helps to keep the performances fresh. After all, it's rare to find anyone who only enjoys only one type of music. Why should it be different for the performers?"