Anybody seeking an exhaustive Britney Spears compilation has been waiting for a collection like 2013′s The Essential Britney Spears. Where other Britney compilations ran no longer than a single CD, this is a double-disc set with over 30 tracks -- more than enough space for all of her hit American singles, although that does mean that there are some singles from non-U.S. territories that are missing in action. Usually, the earliest of these are the ones most notable -- the sugary Born to Make You Happy is the greatest omission, but Don′t Let Me Be the Last to Know, I Love Rock N Roll, and Anticipating are all absent, along with latter-day dance and European singles MMM Papi and Lace and Leather, European singles like Someday (I Will Understand) -- but only hardcore fans will notice what′s absent, as all the hits are here, from ?aby One More Time to Till the World Ends (plus Scream & Shout, the will.i.am hit featuring Spears).