In recording studios, they usually dont care if you do a pitchy take, as long as you do an expressive one. Cos thats what singing is about man,
the feel...
(secondly cos they can tune you pitch digitally later on, hehe)
If not, you're gona sound like one of them choir people.
And the feel, is very hard to teach. cos its somewhat an inhibitation on the singer's part that the feel doesn't come out. So the only advice is to let loose and let it all out, dont be afraid to goof up, its better to goof up practisin then to goof up performing.
breakdown of the elements of the feel include, playing around with the timing abit, eg singing just that quaver of a note before or after the beat to create groove, accentuation of certain notes in a phrase, the attack of your entry, and the attack of every other note, how long you drag a note.. lots more shit
very sterile explanation... but takes away very sterile singing.
Jimi Hendrix doesnt have a superb voice, but he's damn expressive with it. and people dig that.