Ashton, Luke, Michael and Calum rehearsed "Amnesia" at the Forum in Inglewood, California, on Saturday (August 23), a day before the big show. The guys wore their signature band tees as they worked out harmonies and perfected lighting.
The band is up for Artist To Watch at Sunday night's show. Voting is still open for Best Lyric Video -- the socially voted category they're nominated for with Demi Lovato, Katy Perry, Austin Mahone and Ariana Grande. Tune in to see which 5SOS member will have a wardrobe malfunction.