What “Will You Still Love Me Tomorrow” was to the 1960s, “When Will I See You Again” was to the ’70s — girl-group harmonies so laden with left-hanging yearning it felt like it could break your radio apart if the arrangement wasn’t so immaculate. But that was just one facet of Philadelphia’s most successful female vocal ensemble — that yearning took on a slow-boil epic turn on “If and When,” while there’s also the scolding defiance of cradle-robber shakeoff “Dirty Ol’ Man” and the motivational uplift of get-it-together liberation anthem “Year of Decision.”