Mary J. Blige: Herstory, Vol. 1 (Geffen) Blige’s catalogue is so vast and so crammed with remixes that comparing this 16-track best-of to 2006’s 15-track Reflections reveals only that the “I’m Goin’ Down”s are identical and the “Real Love”s and “Be Happy”s different before the vastness takes over—no other song is repeated at all. Nor is anything but the…