Joseph Johannes Clemens Ahrens (April 17, 1904 in – December 21, 1997 in Berlin) was a German composer and organist. Ahrens received early training in organ and choral music with Wilhelm Schnippering in Büren and Fritz Volbach in Munich. He read choral studies at Gerleve Abbey and Beuron Abbey. From 1925-1928 he studied at the State Academy for Church and School Music (now called the Royal Music Institute of Berlin) under Alfred Sittard, Max Seiffert, and Wilhelm Middelschulte. In 1928 he began teaching organ playing and improvisation at the same academy. Between 1931 and 1940 Ahrens was the organist for the Berliner Philharmoniker, simultaneously serving as the organist for the Cathedral of St. Hedwig after 1934. From 1945 to 1957 he was organist at the Salvator-Kirche in Berlin-Wilmersd