He is also a stage director, conductor, librettist, essayist, clinician, and collaborative pianist. Described as a “composer born to write operas” (Chicago Tribune) whose music is “dazzling, unsettling, exuberant, and heroic” (The New Yorker), his opera Amelia was described as “one of the 20 best operas of the 21st century” by Opera News. Hagen’s work often includes collaborations with both mainstream and cutting-edge filmmakers, directors, conductors, choreographers, and musicians worldwide. Groves Encyclopedia calls art song “the center of Hagen’s catalogue.”