Every group has those few singers who seem to have faces that are just not expressive. They might even be aware of it, having been told they need to ‘notify their face’ of all the fun they’re having! Unfortunately, this is exactly opposite of what they likely need.
Lots of us enter fight-or-flight mode when we’re performing or even rehearsing, and we can recognize the facets of the experience: the heart beats faster, we can’t catch our breath, our knees might shake, our bellies might have butterflies or feel tied in knots. Some people who have more dysregulated nervous systems might skip this altogether and go straight to freeze state. Freeze state is a numbed-out energy conservation mode controlled by the DORSAL part of the vagus nerve. The really important thing to know is that the facial muscles are innervated by the VENTRAL part of the vagus nerve, so even in a mild freeze state where a person might feel just a little spacey, the muscles that move the face are not available. This creates the mask-like appearance that we label ‘not expressive’, and demanding that they do a better job of expressing themselves facially will probably feel like a threat and deepen the freeze.
So what do we do?
We go for safety and social engagement. A sense of safety reduces the level of threat that engaged the fight-or-flight system in the first place, and social engagement helps bring the ventral part of the vagus nerve online, which lets the facial muscles move. I love the technique of getting people to have mini-conversations on the risers about things that are real to them: something great that happened to them recently, the best thing they had to eat today, something they love about their kid/dog/grandkid/lizard/whatever, the funniest cat video they’ve seen lately. Then keep the mood exactly as it is, enjoying the lovely social connection established, and go straight into singing. The more socially connected your singers feel, the more likely it is that their faces will be able to show it!