God gave EVERYBODY the ability to change the pitch of their voice to set frequencies in various patterns. that is the mechanics of singing. whether we grow to appriciate that talent enough to commit to hard work perfecting it is our choice. "God given" applies to everything we are, not an adjective to set some above the rest.
in terms of vocal quality, that is purely the luck of the gene pool. each voice is unique and some are better suited for various styles of performance.
in terms of technique, that is a skill that can be learned.
what separates the good from the great is the PASSION.
not to be confused with ambition.
i mean people who love music for the sake of music, the art form, not the 15 year old kid who wabts to be the next kelly Clarkson and thinks they will win purely because they believe.
the best artists and vocalists are the ones that want to advance the art, not just make a quick buck. to leave an influence on an artform and craft stretching to the dawn of time.
Bob Dylan doesnt have the best voice, but his talent for lyrics, understanding how music works and simple love of sharing his ability with others is what made him great.
The source of that passion is anybodys guess. some say God, some say upbringing, but regardless, you could understand everything there is to know about singing, have all the technique in the world, but if you dont care about the music, it comes acros in your performances as dry, emotionless, and dead.