You know that BASF commercial? It goes something like..
"We don't make the things you buy. We make the things you buy better."
Air is like that.
It won't make your high range, but it'll make it better.
It won't make your articulation, but it'll make it better.
It won't make your tone, but .... you get the idea.
Have you ever heard that story about the anthropologist interviewing the tribal elder who insisted that the earth sits on the back of turtle. The anthropologist asks, "What is the turtle sitting on?" The elder replies, "Another turtle."
The anthropologist asks, "What's that turtle sitting on?"
The elder smiles, answering, "You can't fool me. It's turtles all the way down."
So, if your tone rests on your air, what does your air rely on?
Probably relaxation and posture. What does that rely on?
Probably habits and attitude. Below that?