Rock the Farm, an annual concert and fund-raiser for the Wounded Warrior Project, will take place under a tent at Ocean View Farm in Amagansett on July 21 starting at 6 p.m., rain or shine. Steel Pulse, Grammy winners, will play reggae, and Chris Campion, indie rocker and frontman of Knockout Drops, will open the show, backed by Billy Ryan, the guitarist for the Bogmen.