emily-- I love your quote from Zimbabwe! The trick is, until someone proves to you that you CAN make the sound, it's impossible to believe. Before yesterday I would have believed it was impossible too.
You'll appreciate this little parlour trick she pulled during my lesson to teach me what you said ("if you can talk you can sing"):
She told me to introduce myself and say I'm here for my lesson, in a regular speaking voice. I did.
Then she said, "Now say the same thing, but pretend you're a radio announcer and say it in the exaggerated way they would say it." I did.
"See," she says, "You can get that sound into your speaking voice, you just don't know how you did it. A trained announcer is imagining lots of spaces inside their body where vibrations can be produced. They've learned how to control those vibrations to make the sound they want. You don't know yet how to control the vibrations, but you know how to mimic the effect, and you just proved that you can make the sound. Now we'll teach you to control it so you can use it when you sing."
Boy, am I hooked.