free advice to aspiring wannabees- after 20 plus years in around bands music - i have come to the conclusion most often all that is needed for a band/artist to succeed is that the/their singer be fortunate enough to be borne with a voice (muscle configuration in voicebox) that allows you to sing comfortably in higher range than most people can (this generally applies to guys too) thus fooling the listener into thinking they are hearing something out of the ordinary - making it standout
of course there is a lot of other factors involved, innate timing, inflection, uniuqness of timbre and voice, natural pitch/ear - but these are secondary to that first requirement and can be learned by rote
their are many exeptions of course to the high register rule - Tom Waits (my fav vocalist/writer/performer these days - wish he would tour - fat chance
) tex perkins, nick cave - were sheer force of personality/talent/writing win over the high register factor
of course a strong connection to your soul and left brain is essential too