If you like some jazz in your pop or pop in your jazz, this is the best stuff in...well, two decades.  This especially holds true if one is a bop or cool jazz fan.  There's Kind of Blue all over this album.  The tracks were recorded by a core of live musicians, so TvN has more of a live feel than their masterpiece Aja.  The integration and communication between instruments is absolutely amazing for a studio album - a seamless conversation.  If the first 7 Dan albums were beautiful 2 dimensional and lyrical chess, the Two Against Nature has a special 3-dimensional quality.  While LA jazz permeates Royal Scam, Aja, and to some extent Gaucho, Two Against Nature goes straight to the 50s source (over a funk backdrop) - the heros of Fagen and Becker.  The album can be snappy (Janie Runaway) or just plain gorgeous (Almost Gothic).  Those songs along with Negative Girl and West of Hollywood are among Dan's finest moments.  I can honestly say I rank this one close to Aja and Katy Lied.  Well deserving of the Grammy accolades.  However, if you are a rock fan expecting to hear a screaming Elliot Randall solo, forget it.  This is not your father's Steely Dan.