Charles Halka writes acoustic and electronic music for concert, dance, and opera, and his works are often inspired by language, visual imagery, movement, and human experience. His music has been performed in North America, Europe, and Hong Kong, and performances include those by the Cabrillo Festival Orchestra led by Marin Alsop, the Mexican National Symphony Orchestra, counter)induction (New York), Volti (San Francisco), ÓNIX Ensamble (Mexico), PRO ARTE eNsemble (Russia), Aquarius (Belgium), Duplum Dúo (Mexico), the Boston New Music Initiative, Jauna Muzika (Lithuania), the Armonas Trio (Lithuania), and Pictures on Silence (Baltimore). As a 2008-09 U.S. Fulbright grantee, he spent a year in Vilnius, Lithuania researching Lithuanian music and writing an opera in collaboration with director and librettist Marija Simona Šimulynaitė. The opera, Julius, was premiered in 2010 in Vilnius, and a choral excerpt from the opera, Dipukų Rauda, was performed at the ISCM World Music Days 2012 in Belgium. In 2011, Round and Round, based on a work by the American music patron Elizabeth Sprague Coolidge, was premiered at the Coolidge Auditorium of the Library of Congress, and in 2013 he premiered a revised version in Hong Kong at the Intimacy of Creativity partnership led by composer Bright Sheng.