Vivian Green has a soft voice, but it often builds into boisterous crescendos. It wouldn't be surprising to see grown men weeping at the sound of it, or women gritting their teeth with envy. Her songs can wrap around you like a cozy blanket and then wring the inhibitions right out of you. The few who've already seen Green perform know it's a surprisingly stirring, emotional experience. It's also a little unnerving. This 23-year-old Philadelphian is too young to have such an explosively soulful intensity. But hey, that's why she has the deal with Sony and a new album (A Love Story). And that's why her audiences just have to sit back, mystified.