Richard —, German composer of operas Parsifal and Lohengrin (6)
I believe the answer is:
wagner
(Other definitions for wagner that I've seen before include "Tannhauser composer" , "German cycle-maker" , "German composer of The Flying Dutchman" , "German opera composer" , "Richard . . . . . . composer of 'The Flying Dutchman' and 'Lohengrin'" .)