Charles Rosen, on Berlioz's "frequent failures"

It is, of course, impossible single-handedly to invent an entirely new musical language, and we can understand Berliozโ€™s frequent failures. โ€ฆ Perhaps most disconcerting of all are moments when Berlioz has a genuinely original inspiration but does not know what to do with it. The wonderful contrast of soft high flutes and soft low trombones in the โ€œHostiasโ€ of the Requiem is an example: having invented this impressive juxtaposition, Berlioz can thick of nothing better than simply repeating it many times - after the third time, it loses its novelty and becomes merely bizarre. This section, however, should not prevent one from appreciating the magnificence of the opening pages of the Requiem, and of the โ€œLacrymosa.โ€ I have finished by dwelling briefly on Berliozโ€™s failures because an uncritical attempt to justify the totality of his work prevents one from appreciating the magnitude and the nature of his successes.

From The Romantic Generation, 568. (1995).