The title of 23-year-old Patti Rothberg’s debut alludes to her years of musical training before some of the toughest audiences you can find: busking in a New York City subway between the No. 1 and No. 9 trains, where she was quite literally discovered last year. Rothberg’s travails have lent a hard blues–tinged edge to her airy, delicate voice, making it an instrument versatile enough to tackle either urban-folksy, acoustic-tinted songs like “Looking for a Girl,” or heavier, faster, in-the-rough rock songs like “Treat Me Like Dirt.” The anxiety she betrays on such numbers might inspire the obvious comparison to fellow Bitter Female Alanis Morissette, but the ex-Canadian-dance-pop-queen’s ironic brand of venom contrasts with Rothberg’s more restrained delivery and more personal lyricizing. Oh sure, Rothberg can match angst with anyone. But there’s a zest and zing to the way she provides her guitar accompaniment, especially as she romps through “Up Against the Wall,” the very best of her pulsing, up-tempo crowd-pleasers; when I saw her play it live, she took her guitar and played the solo behind her head, à la Hendrix. Rothberg doesn’t just perform her songs, she attacks them, playing guitar on all of Between’s tracks with a sense of urgency that should catch your attention.