Blues soloist Eli Cook will perform at 6:30 p.m. Friday at Flat Iron Crossroads in Gloucester. Cook has opened for the late B.B. King and has performed at the Kennedy Center and the Library of Congress. He has been featured in Guitar Player and other magazines. Doors open at 5 p.m. Food will be by Shore Bites Food Truck, and beverages will be available for purchase. The cover charge is $5. For more information, visit flatironcrossroads.com....