Wagner's operas represent the fullest musical and theatrical expression of German romanticism. His ideas exerted a profound influence on the work of later composers. For the principle of sharply differentiated recitative and aria, Wagner substituted his "endless melody" and his Sprechgesang [sung speech], calling his operas music-dramas to signify the complete union of music and drama that he sought to achieve. He thought that music could not develop further with the resources it had employed since Beethoven's time, and he maintained that the music of the future must be part of a synthesis of the arts.
Adapting German mythology to his dramatic requirements, Wagner applied to it an increased emotional intensity, derived from the harmonic complexity and power of Beethoven's music, to produce what he termed a "complete art work." He achieved a remarkable dramatic unity due in part to his development of the leitmotif, a brief passage or fragment of music used to characterize an episode or person and brought in at will to recall it to the audience. At the same time, Wagner greatly increased the flexibility and variety of his orchestral accompaniments. He was responsible for the productions of his works from libretti to details of sets and costumes.
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