Of the 24 semifinalists chosen last week, the Top 12 girls will perform for America for the first time. Then it’s up to the viewers to vote for their favorites. Who will survive and who will go home?Performing tonight are:Alaina AlexanderAmy KrebsAntonella BarbaGina GlocksenHaley ScarnatoJordin SparksLakisha JonesLeslie HuntMelinda DoolittleNicole TranquilloSabrina SloanStephanie Edwards