James Kwak began studying cello with Barbara Levy and attended the Preparatory Division of the Juilliard School of Music, where he studied with Ardyth Alton. During high school, he was principal cellist of the Juilliard Pre-College Sinfonia, the Estherwood Festival Orchestra, and the All-Eastern Orchestra, and was awarded the Pre-College Prize upon graduation from Juilliard. James attended Harvard College, where he took lessons with Colin Carr and played in chamber music classes taught by Leon Kirchner, Earl Kim, and Lynn Chang. He was also principal cellist and later music director of the Harvard-Radcliffe Bach Society Orchestra. During graduate school at the University of California, Berkeley, he was principal cellist of the UC Berkeley Symphony and also played in the AIMS Festival Orchestra.

James did other things for twenty years—including working in the business world, going to law school, and becoming a law professor—before beginning to play cello again and taking occasional lessons with Edward Arron. He currently plays in the New England Repertory Orchestra and the Worcester Symphony Orchestra and lives in Amherst, Massachusetts.