Let us begin with the English Archphilistine, Bennett, in whose Letters from Bayreuth we are told among other funny things that:
"we have in Rheingold the continuous flow of formless music" which 'streams along the mind, so to speak, without passing into it,' and 'offers but little of an intelligible character to lay hold of.' This music 'has no meaning by itself.' The dialogues in "Die Walküre" are 'most terribly wearisome and painful sounds,' which excite the mind 'to a state of intense irritation.' Nevertheless, there are things in this music-drama which "approach as nearly as possible to that which we commonly know as music." Of the music in the "Gotterdammerung" the memory 'retains an impression definite only with regard to features which produced weariness.' As a music-drama, this work 'disappoints, the more keenly because of the magnificent opportunities supplied by its situations for really sublime musical effect.'"
--"Wagner and His Works: The Story of His Life, with Critical Comments", Volume 2