Selena Gomez will perform at the Justin Timberlake & Friends benefit concert at Planet Hollywood in Las Vegas on Oct. 23 along with Christina Aguilera, Sean 'Diddy' Combs, Lady Antebellum and more. Attendees will receive admission to the final round of the tournament on Oct. 24. Tickets to the concert go on sale through Ticketmaster on Aug. 21 at 10 AM PT.