Appropriately enough for the final volume of Universal's monumental series The Complete Motown Singles, The Complete Motown Singles, Vol. 12B: 1972 is filled with endings. The last single the Four Tops cut for Motown is here (they'd re-sign about a decade later), as is the last song Smokey Robinson made as a member of the Miracles, and elsewhere there are transitions: Diana Ross made her silver screen debut and Michael Jackson stepped away from the Jackson 5 with "Ben," his first solo single to reach number one. All this is part of the bigger story of Motown firmly establishing its headquarters in Los Angeles, severing its ties to Detroit. Much of this story was told in the accompanying box set, The Complete Motown Singles, Vol. 12A, which chronicled the first half of the year. Vol. 12B covers the last six months of 1972, taking in 100 songs over the course of five CDs. It's certainly possible to hear the fracturing of the great Motown coalition, not only through the fading of '60s stars but hearing the label pursue such ventures as MoWest (the modern-minded Californian subsidiary opened once the label relocated to the Left Coast) and also the variety of odd pop pursuits, which amounted to odd hippie singles by Bobby Darin, Lesley Gore, and Frankie Valli, groups that rode Rare Earth's coattails, and attempts to cash in on such early-'70s trends as the horn-fueled Chicago or AM bubblegum pop -- and there's also a fair amount of new soul that sounded indebted to Holland-Dozier-Holland's work at their label, Invictus. Amidst all of this, Marvin Gaye did his blaxploitation soundtrack Trouble Man, the Temptations had their last great hit with "Papa Was a Rollin' Stone," and Stevie Wonder hit his stride with Talking Book and "Superstition" and produced his ex-wife Syreeta Wright. No matter how strong these iconic hits are, there aren't a lot of them, especially when compared to the bounty on previous Complete Motown Singles boxes, but what makes this box compelling are those detours, bad ideas, one-shot wonders, and oddities. Sometimes a gem can be found among all these songs but what really matters is the cumulative effect, how the chaff combines with the classics to form a complete picture of Motown in 1972 and, in the process, the sound of soul and pop in that year. It's a shame that the series has to reach a conclusion -- the late '70s would've provided fascinating listening -- but this splintering does indeed suggest how the classic Motown era had drawn to a close.