London-based experimental, electronic, post-rock and pop music outfit Stereolab return to marketplace with a brilliant collection, Not Music, an accompaniment to their underappreciated 2008 effort, Chemical Chords.  While it stands alone as a record in its own right, the tracks included on Not Music are cues left out from their last record; it follows the format of some previous b-sides and rarities collections they’ve put out such as Fab Four Suture, Oscillations from the Anti-Sun and the Switched On series.  Not Music is perhaps not as cohesive as Chemical ...