Music's brightest-shining supernovas, from Taylor Swift to Iggy Azalea, spent the weekend in Vegas for the 2015 Billboard Music Awards. The year's chart toppers were honored live and in-person for their radio hits, but not before bringing their beauty A-game to the red carpet. Hollywood awards shows are all about the glamour, but Vegas is where stars show their trendy side. Behold the most enviable hair and makeup looks from the Billboard Music Awards 2015.