Complex sentence: In 1668 his daughter Anna Margarethe married the great Danish-German composer Dieterich Buxtehude, who was the organist at the Marienkirche in Lübeck until at least 1703.
Split into simpler sentences: In 1668 his daughter Anna Margarethe married the great Danish-German composer Dieterich Buxtehude. As the organist at the Marienkirche in Lübeck until at least 1703.