He plays with pitches and scales. He makes sounds with his mouth, and experiments with the shape of his mouth and its effect on the sound. He plays with various rhythms to see how they change what we tend to do with vowels, and then he tries out a variety of consonants in a variety of interval skips to see how they work. The sounds can be silly or pretty. Really, it sounds like play, and I'm unclear whether he knows that others can hear him. In his mind, he must be imagining how to newly present images to singers to help them sing more precisely and more beautifully.
I've sat under his leadership probably six times, and not once have I heard him repeat a metaphor or offer an explanation in the same way. His teaching is always new and fresh and filled with metaphors of all sorts. You won't hear about the mouth and the lungs or actual body parts, and you hear little at all about what is on the page from which you are singing; instead you hear about birds, flames, eggs, paintings, houses, relationships, emotions - these all figure into his special way of enticing singers to go beyond reading what is on the page and present their sound as something magical. And truly, magical is the only way to describe the results he is able to achieve.
Brouwers is a conductor in the Netherlands who directs a wide variety of chant and polyphonic groups. His singers are very lucky to have him. He is the consummate musician, a person who lives and breaths music as prayer. Americans have the opportunity to experience his direction at the Sacred Music Colloquium. It is unforgettable.I should add too that one rarely finds such humility and old-fashioned sweetness of countenance in a musician of his level of accomplishment. This too is an inspiration.