Left Hand Free//Alt-J

It feels like Christmas! Alt-J have another new track out this week ahead of their September 22nd release of forthcoming album, This is all yours. Things are really happening for the boys, it seems, as it appears they've left behind their iconic ambient sensibility for a more 70s rock infused sound. While I was initially wary of 'Hunger of The Pine' (though it's grown on me now) I immediately liked 'Left Hand Free'. There is something intoxicating about the opening riff and subsequent cowbell. Thoughts?