Avant garde? New Classical? Whatever you want to call it, this type of music explores areas way outside of what you’re used to listening to. From one of my favorite composers, Karlheinz Stiockhausen, here is Klavierstueck IX.
Remember: there’s a huge difference between good ugly and bad ugly. Besides, 4/4 is sooo overrated (and overused).
If you like what you hear, you’ll probably also enjoy Stockhausen’s Gesang der Junglinge, which has always been one of my favorites. You can find some of Stockhausen’s works over at Amazon.