German composer. He was connected with the Reformation and became a pastor at various churches in the Geislingen and Ulm regions. (He was not the same as Benedictus de Opitiis nor Appenzeller, whose works have sometimes been attributed to him.) Ducis appears to have been an irascible character, given to wife-beating, though intellectually a friend to humanism. He composed both florid Catholic music and simpler chorale settings published by Rhaw for Lutheran use; his style is closer to that of Isaac and Dietrich than that of Josquin Desprez, and his use of the cantus firmus is unusually free.