John Karl Hirten’s compositions have been been favorably reviewed in The Diapason, The American Organist and the Journal of the American Choral Directors Association. His music is published by G.I.A., Concordia, Augsburg, Trinitas (OCP), Church Publishing, and others. He has been commissioned by orchestras, churches and organizations such as the American Guild of Organists, not to mention individuals looking to enhance their contemporary repertoire.

He holds a Master’s Degree in Organ Performance from the Manhattan School of Music in New York City. He has performed in Europe and the Eastern United Styates, and throughout the San Francisco Bay Area, having appeared with the San Francisco Symphony, the Berkeley Symphony, the Oakland East Bay Symphony, and the Oakland Ballet. For twenty years he was a monthly performer at the California Palace of the Legion of Honor, an art museum that boasts an E.M. Skinner pipe organ, playing well over three hundred recitals there.

Mr. Hirten has been a church musician since the age of fifteen, when he was hired as a cantor for his parish church in Washington, DC. He has served as organist at the Fordham University Chapel (Rose Hill Campus) in the Bronx, Trinity Church on Wall Street in New York City, and St. James Cathedral in Brooklyn, and Director of Music at Old St. Mary’s Church in San Francisco. Since 1995 has has been Director of Music at St. Stephen's Episcopal Church in Belvedere. He has worked extensively at synagogues, taught organ at a Baptist Seminary, and has written music for the Lutheran Church. His varied background in church music has led to his being described as an "ecumenical wonder" (GIA Quarterly).