These hand movements train us to focus on clean formed vowels, and help to ingrain them in the body, so that these unified vowels become a habit.
The formed vowels are ‘ee’, ‘ay’, ‘ah, ‘oh’ and ‘oo’, and these are the hand signs that I use.
There’s something about the isometric nature of the pull or push in each one that creates a taller, richer, more unified sound.
And as a director, I find it really useful to be able to use these signals to remind choruses to lock in to a vowel. When my singers have rehearsed these movements, they already know what this sound/movement combination feels like – and can reproduce it when they see me giving them the cues.
Here’s the video I’ve just made so that you can see the hand movements I use… (So new at this that I have yet to figure out why sometimes the first few seconds of sound have no accompanying video. Just hang in there, and the video does appear)