Alice is doing a service here. One of the most important things said is:
"I think the hardest thing to do for most beginners is to concentrate on the music instead of the emotion. It feels awful not to concentrate on the emotion, but concentrating on the music will eventually pay off."

When you go for the emotions, you can sometimes tie up the cords.

As to vocal quality, one of my favorite singers is Louis Armstrong. (Go figure)

Then, Tony Bennett.

I like Jussi Boerling and Pavarotti too and Renee Fleming.

They all have found their individual voice and just like a fingerprint, everyone's voice is different. The trick is to find your natural voice and this comes with some kind of training.

I think it's very important to find a good vocal teacher who can mirror correct technique for you which you can't get from books and tapes.