Word Study
music drama
CIDE DICTIONARY
music drama,
An opera in which the text and action are not interrupted by set arias, duets, etc., the music being determined throughout by dramatic appropriateness; musical drama of this character, in general. It involves the use of a kind of melodious declamation, the development of leitmotif, great orchestral elaboration, and a fusion of poetry, music, action, and scene into an organic whole. The term is applied esp. to the later works of Wagner: “Tristan und Isolde,” “Die Meistersinger,” “Rheingold,” “WalkÜre,” “Siegfried,” “Götterdämmerung,” and “Parsifal.” [Webster 1913 Suppl.]
For further exploring for "music drama" in Webster Dictionary Online