Wagner's orchestra acquired gradually the functions of the Greek chorus, in that it takes part in the action to publish that which is beyond the capacity of the personages alone to utter. He unfolds thoughts, emotions, motives and passions by means of mode, harmony, rythm, time and the orchestration. By applying the principles of augmentation to a phrase in the three phases of melodic, harmonic and instrumental structure, he illustrates the tragic growth of Siegfried. He wrote his own librettos so that his works would be consistent. "Tristan and Isolde", "Die Meistersinger", "Der Ring des Nibelunger" and "Parsifal" realized his conception of what a poet composer should be. Music had usurped the place in lyric drama and music is a medium only and not an end of dramatic expression. His leitmotiv, infinite melody and symbolical themes gave his orchestra color. He used musical declamation for recitative secco, employed choruses with intelligent regard, and originated arias from the situations. Wagner lived for pure singing and did not make abnormal demands upon the voice like those of Strauss' "Electra". He has long solo passages and orderly development of orchestral themes, as different from Debussy whose sounds are not connected. Wagner elevated the orchestra from a mere accompanying force to an essential factor. He maintained that formal song should be abolished, that the dialogue should be musical and that the orchestra should have an orderly development of melodic material save when the climaxes justify an apparently disconnected dramatic melodramatic method. Damrosch criticizes Wagner because he says everything in his orchestra, and his singer is too little considered.