This is interesting! I'm a newbie, and I tried to read all the posts before responding (but some were really long) so please forgive me if I repeat what someone else said, but, 3 things:

Rock and roll is rock and roll. You really can't teach it! :-D It's something you feel deep in your soul, and if you're lucky enough to be able to express it, well, it's a natural occurrence. My two biggest vocal influences were Ann Wilson from Heart, and Robert Plant from Led Zeppelin. I took lessons on "proper" vocal technique from a classical vocalist, and when I brought her Heart and Zeppelin records, she just shook her head and said, "Well, I'll show you diaphramatic breathing and that's about all I can do. I've never heard of this music and it goes against everything that I teach!" :-D So I learned deep, diaphramatic breathing (which is what I use before I go to belt out "Barracuda") and she also taught me about "head voice", and using the bones in my face and my mouth as a "mini-ampitheater".

Since I was about 10, I wanted to be a female version of Robert Plant (even though he's a female version of himself, LOL) and I've been "screaming" Zep tunes ever since. Warm up, warm up, and then, warm up! Don't EVER try this stuff cold, right off the bat. I warm up for at least 45 minutes before I even attempt any rock stuff, sometimes longer.

You can sustain considerable damage, even get nodes on your chords, but they can be removed and you can resume your career. I mean, you don't really want to go there, but if it happens, there's surgery.

I love cigarettes like no other, but I don't smoke. It lessens my ability for deep breathing. I'll smoke an ultra light cig when I'm drinking now and then, but normally I don't smoke. I find that brisk walking 2 miles every day helps my breathing too.

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You're supposed to be grooving as hard as you can, all of the time. - Stephen Gaskin