American Idol is nearing the end! The final four contestants of the season performed last night, with a little mentoring help from Lady Gaga, and we took a closer look at the style of the two leading ladies Lauren Alaina and Haley Reinhart. Each songstress performed two songs, and they played up their personalities with their looks. Reinhart elevated her pop look with a Terani look (left), while Alaina added glam to her country style with a brick red Tony Bowls dress with cheetah-print lining (right). The show's costume designer Soyon An gave InStyle the inside scoop about the rest of their looks—click "See the Photos" for all the details.