#2 Listening
I believe that the number one rule in singing or band or theatre is listening. A singer has to listen to themselves as they are putting out sound, listen to the other singers and blend, listen to the musicians or track and blend with them. Listen for harmonies, harmonics, listen for conversation type interchange....listen to the birds, your heartbeat, your breathing, other people’s breathing, the sounds around you, the car motors, your loved ones words, other people...you get the idea...practice listening