Famous for his work with the alternative band Yellowcard, this bassist and guitarist is also notable for his earlier membership in the bands Staring Back and Near Miss.
In his teens, he performed with a Georgia-based band called Zero Racecar and went on to form a group called Lancaster.
During Yellowcard's early 21st-century hiatus, Portman studied business at Macon State College in Georgia and formed a metal group that he named Great White Lion Snake.
He spent the first decade of his life in Madison, Wisconsin, and the remainder of his childhood in Atlanta, Georgia. After launching his music career, he lived and worked in Southern California and Nashville, Tennessee.
He and vocalist Ryan Key are both known for their membership in Yellowcard.