2015's finest jams tend to be defined by major key or "bliss" jamming (your 8/22/15 Caspians and 12/30/15 Gins of the world); this one takes the opposite tack, delving into darker and stranger realms than even much of 3.0 tended to plumb (i.e., the realms 2.0 regularly traversed). I'm not sure this is on the same tier as the year's true classics, but it's a damned fine jam that makes the absolute most out of every second of its running length and is certainly part of why 12/31/15 is such a superb show. Great transition into Piper, as well.