This one is so simple, and really effective. It came to us from Barry Towner, a Barbershop Harmony Society presentation judge.
When some of your group are singing a wide ‘ee’ or ‘ay’ vowel this simple director’s movement will fix it.
To get to the starting position:
Left arm straight out, palm down. Bend elbow to 90 degrees – so that the arm is in the position it would be in if you were standing with your forearm resting on a counter or bar.
With the arm in this position, have the choir sing a sustained pitch on an ‘ee’ vowel.
Now, with the elbow still bent to 90 degrees, trace a quarter of a circle upwards with the finger tips of the left hand. The left palm will end up facing to the right and the finger tips will be pointing upwards. The movement will remind you of a speedometer going from zero to sixty. (Actually – this analogy would work better if you were using your right arm)
Anyway – as the forearm begins to move, and the fingertips begin to point upwards, the choir’s ‘ee’ vowel will become taller and more matched. They can’t seem to resist!