Well, I haven't been keeping tabs on the experimental scene a whole lot lately but from the last few years, there's things like Aphex Twin, Merzbow and Múm. Even Radiohead created a bunch of new sounds, maybe not so much on King of Limbs but undeniably for Kid A and that was only 11 years ago in the many thousands of year old art of music. There's never been a point in history where music hasn't progressed in some way. You could say that it's all melody, rythem, harmony etc. but then all you're really saying is that music is music (and there's lots of it that dispenses with some or all of those things).