Many of of the great composers of yore wrote for operas, ballets, theater, and such which is the equivalent to movies today so I think that's an apt comparison.

Many of of the great composers of yore wrote for operas, ballets, theater, and such which is the equivalent to movies today so I think that's an apt comparison. That said much of the experimentation in classical music has been worked on and refined and yielded music which worked well later. For instance Stravinsky's The Rite of Spring sounded weird to the audience of the time, but we've come to accept it and many of its devices have been used to good effect (for instance by John Williams). One reason I think is audience have grown to accept and understand these sounds. Another reason I believe is the context. I think often we hear these together with a movie and it fits emotionally, but when we hear the music in isolation in a concert hall it we don't get it. So, I think classical (and jazz and music in general) has always been weird and people have tried to push the boundaries and generally it's brought good results over time even though we may find it difficult to appreciate it right away or without the right context.