music drama

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun An opera that avoids discrete numbers such as arias, recitatives, or ensembles, and in which the music reflects or embodies the action of the drama.

from the GNU version of the Collaborative International Dictionary of English.

• 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.”