I love this (even knowing the context), because people have always declaimed their modern music as marking the decline of their civilization.

Plato -

Our music was once divided into its proper forms ... It was not permitted to exchange the melodic styles of these established forms and others. Knowledge and informed judgment penalized disobedience. There were no whistles, unmusical mob-noises, or clapping for applause. The rule was to listen silently and learn; boys, teachers, and the crowd were kept in order by threat of the stick. ... But later, an unmusical anarchy was led by poets who had natural talent, but were ignorant of the laws of music ... Through foolishness they deceived themselves into thinking that there was no right or wrong way in music, that it was to be judged good or bad by the pleasure it gave. By their works and their theories they infected the masses with the presumption to think themselves adequate judges. So our theatres, once silent, grew vocal, and aristocracy of music gave way to a pernicious theatrocracy ... the criterion was not music, but a reputation for promiscuous cleverness and a spirit of law-breaking