Vampire Weekend, The Avett Brothers, Pretty Lights, MGMT and Robin Thicke are among the acts slated to appear at the Virgin Mobile FreeFest. The annual, free music festival will return to Columbia, MD’s Merriweather Post Pavilion on September 21.
Black Joe Lewis, Chvrches, Washed Out, Sky Ferreira, Icona Pop, City and Colour and Little Green Cars are also slated to appear.

Though tickets do not cost money, fans need to obtain an “on free” ticket to attend the event. Tickets will be made “on free” on August 9 at Noon EST via TicketFly. A special pre-sale being held a day earlier for Virgin Mobile customers, Facebook friends and Twitter followers as well as previous Virgin Mobile festival ticket buyers.