A conductor embodies the expressive intent of the composer and displays signals to that effect.
Singers in the choir must be able to see and interpret them, and here's how that works:
The brain is made of specialized cells called neurons. Cells communicate with electrical and chemical signals that can be measured, which is how we have learned that certain parts of the brain work on certain tasks. Within groups of brain cells that work on certain tasks, some of those cells not only fire when you work on that task, they also fire when you observe someone else working on it. They are called mirror neurons.
Mirror neurons were discovered by a group of scientists in Italy lead by a guy named Vittorio Gallese. They were observing the neurons that fired on a monkey when it picked up food--let's say peanuts. One day, a researcher walked in the room and picked up a peanut. The monkey saw it, and some of its peanut-picking-up neurons fired again, even though he wasn't actually doing it himself.
And this, my friends, is the neurological mechanism of empathy. When you empathize, you feel what the other person feels. "I feel your pain," you might say. And, in fact, the study of mirror neurons shows us that we really do feel other people's pain. And pleasure. And everything. Let's examine a few more examples of this.
It's 1:15 in the afternoon in a 10th grade geometry class. The teacher is doing sample problems on the board. The room is about 80 degrees. Kids are zoning out, staring like zombies. Inside the brain of one kid--let's call him Greg--the brain discovers that he has been breathing shallowly for a few minutes and the oxygen level is too low. Time for a nice deep breath. A certain group of neurons fires and Greg yawns. The kid next to Greg, Alex, observes Greg's yawn, and some of Alex's yawning neurons fire. These are his yawning
mirror neurons. Yawning is a hair-trigger reflex. Upward movement of the soft palate and downward movement of the back of the tongue are enough to set it off. So those few mirror neurons firing in Alex's brain are enough to make him actually yawn. Then Hannah, sitting next to Alex, yawns... and so on and etc.
Scientists calls it "social yawning." The more you like a person, the more connected you are to them, the more likely it is that their yawning will make you yawn. Did you yawn when you read the description? Congratulations! You're a highly empathic person! If you didn't yawn, don't worry, empathy can be increased, but that's another post...
Another example:
If you're watching America's Funniest Home Videos, you're likely to see a male person come to harm by landing heavily on something between his legs. You cringe (highly empathic folks may even cringe reading my extremely dry, generic description of the event). You think "that's gotta hurt." My husband uses the phrase "that hurts just to look at." And he's right. Our brains understand what the guy in the video is experiencing because we have experienced it, too (to whatever degree), and so some of those neurons fire when we observe it. And in firing, they cause us to experience just a tiny bit of it.
Did a movie ever make you cry? They spend two hours teaching you about a character, letting you get to know her, making you care what happens to her. So at the end of
The Color Purple, when Whoopie Goldberg runs across the lawn to hug her children, we feel for her. Literally.
Empathic communication is effortless, involuntary, and instantaneous. There is no processing of thought--your brain cells fire because you observe something. That's it. What action results will vary, but the experience of empathy is inevitable.
So, conducting.
Say you're sitting in the choir, waiting to start singing. The conductor is standing in front, hands raised. She takes a deep breath, her hands drop a bit, and you observe these things. You have experienced breathing that way, so your breathing mirror neurons fire and you experience her breath with her. You also know cognitively that you're supposed to breathe, too, so you do.
Let's look deeper. The song is "To be sung on the water" by Barber. Before you start singing, you see the conductor's face is relaxed, eyes soft and wide, just a hint of a smile. You know her, you can interpret her expression: there's some love, a little awe. You've got mirror neurons for that, too. So you let her influence you, and you feel a little warmth, your energy grows a little more intense. When you breathe, it's with a hushed reverence, imagining the object of your affection, remembering a night that your life changed.
Will that make you sing differently?
You bet yer bippy.
Art and science, science and art. They will answer each other's questions.