So when you sing, How do you change your voice from medium, high, medium, and then Low without damaging your voice and preventing to crack? Like Justin Bieber Or something (no haters please, just using him as an example and i know hes a guy but im just using him as an *example* of those kinds of notes and vocals okay ??) i've been practice singing since the day i learned how to talk. anybody have any tips, videos, ect. for me ? (BTW, I'm a Girl) reasonable answers please ? 