The Search for Soul: Beatlemania was rekindled briefly this year with a set of Fab Four remasters. But in recent years, obscure soul-music reissues have sparked a different obsession. Today: we look at the quest for “outsider soul” at labels like Numero Group, Wax Poetics and Soul Jazz. Guests include Ben Greenman of The New Yorker and Syl Johnson, the singer-producer behind ‘60s songs like the much-sampled “Different Strokes” and “Is It Because I'm Black?”