Begin by taking a deep breath and letting it all the way out with air sound.
Listen with your mind’s ear for a tone.
On the next breath using any vowel sound, sing the tone that you have silently perceived on one comfortable breath.
Listen to the whole field of sound the group is making.
Select a voice distant from you and tune as exactly as possible to the tone you are hearing from that voice.
Listen again to the whole field of sound the group is making.
Contribute by singing a new tone that no one else is singing.
Continue by listening then singing a tone of your own or tuning to the tone of another voice alternately.
Always keep the same tone for any single breath. Change to a new tone on another breath.
Listen for distant partners for tuning.
Sound your new tone so that it may be heard distantly.
Communicate with as many different voices as possible.
End when everyone else does. It happens.