Seriously guys, with every song released I'm getting more and more excited about the new album! This is second track off alt-J's third album Relaxer (coming out in June, so the wait is almost over). It's been long 3 years since their previous album and I definitely hear a more exciting trend here as opposed to their sophomore effort. Apparently this is the track they've been working on for a very good while.
Judge for yourself, but I find this grand and a bit of a very pleasant sonic madness.