After four albums of exceptional, if introspective, folk-pop musings, it's something of a shock to find Erin McKeown turning her attention to jazz gems of the '30s, '40s and '50s. Nevertheless, she does a credible job of capturing the spirit of those songs with a wink and a nudge of irreverence and enticement. Though an able frontwoman, she doesn't ooze the simmering sensuality that ought to accompany the material's smoke-ringed sensibilities. However, when she hands the musical reigns to her small but assured back-up band, she literally gets in the groove via sheer exhilaration. Opening track "Get Happy," one of the set's better-known entries, starts out as gospel shout-out, only to suddenly detour into jazz and jive. Likewise, "Paper Moon" becomes all but unrecognizable under the influence of its samba-like sway, while other songs are fast-paced performances propelled by kinetic drumming and brassy embellishment. McKeown's shift in direction may be unexpected, but if this is the work of a sinner, there's no reason to repent.