Now this is something completely different from anything else on this list until now. It is a programmatic symphony, but there is nothing particularly new about that, Beethoven had done it before with the Pastoral, its originality lies in its psychological depictions.
This might be the first piece of truly psychedelic music, composed under the influence of opium, this symphony follows the changing mental states of an artist culminating in a nightmarish hallucination set at a witches Sabbath.
Same conductor and orchestra, but eight years later than the recording I posted. You get the idea!
The music is extremely evoking throughout, caring much less about harmonious beauty than depicting altered mental states, but achieving both at the same time. A truly original piece of music which is a joy to listen to attentively throughout.