I think that we can discern three stages of the reception of music since the 18th century. The first stage, up to the first quarter of the 19th century, is one where a very sophisticated aristocracy employed composers and musicians to provide music for their private enjoyment. The music-loving members of the aristocracy were very knowledgeable and provided patronage and employment for all the composers we know so well such as Bach, Haydn, Mozart, Beethoven and all the lesser ones. The only other significant employer of composers in this period was the Church (who employed Bach for much of his career).
Then in the 19th and early 20th century the source of employment shifted from the aristocracy, who lost a great deal of their power and prestige following the French Revolution, to the middle class. They tended to synthesise the moral foundation of the lower class with aspirations to some of the refinements of the upper class, including the enjoyment of classical music. This period saw composers beginning to derive most of their income from publishing music, from public concerts and from teaching music. Chopin, for example, derived most of his income from giving private lessons in Paris. Most of the symphony orchestra concert series and the necessary concert halls were established in the 19th century. The newly prosperous middle class bought music and instruments (most middle class homes had a piano) in great quantity. The profession of the music critic also began as they also bought periodicals talking about music. At the very end of this period the gramophone was invented and people started purchasing recorded music.
In the 20th century much of this remained, such as the concert series, but other forces became important. Music in the 19th century was crafted to appeal to middle class tastes. A lot of it was considerably cruder than the more refined 18th century music. In the early 20th century a reaction to this occurred. I'm not sure if I can even give a complete explanation, certainly not in this brief note. But we start to see the artistic movement we call "modernism". Partly a reaction to the too-obvious tastes of the middle class and partly a reaction to the violence and inhumanity of the First World War, composers began to write much more acerbic and challenging music. They were, I suppose, composing for a new urban elite. In any case, as the century wore on, modern music became more and more difficult and had a smaller and smaller audience. Two other trends became important: popular music became a huge economic force and some of the classical music world "went retro" and began rediscovering older forms of music: Baroque and pre-Baroque.
I guess the conclusion I am leading to is that the function of music has changed radically. In the 18th century it was like a kind of conversation between people of considerable intellectual capacity. In the 19th century it became more sensationalistic and emotional. In the 20th century it fragmented into many different categories: some soothing, some challenging, some intellectually complex and some, like Calvin Harris and EDM, designed to function on a very basic level.
Shall we have examples of all three? Sure! First, 18th century refinement. This is the Piano Concerto no. 27 in B flat, K. 595 with Maria João Pires, piano and the Chamber Orchestra of Europe conducted by Trevor Pinnock:
Then some emotional and sensational 19th century music. This is the Symphony no. 7 in D minor, op. 70 by Dvořák. The Royal Stockholm Philharmonic Orchestra is conducted by John Eliot Gardiner:
Finally, hmm, well, there are so many different styles and genres in the 20th century... But let me pick one piece that at least draws on a few of those styles. This is Six Pianos by Steve Reich, which is a kind of be-bop minimalism: