Singer-Songwriter Carpenter at Roxy

Early in her Roxy show Thursday night, Mary-Chapin Carpenter told an odd little story about recently being chased down a backstage hallway by a confused woman inquiring, “Karen? Karen?”

This D.C.-bred country-folk-rock singer is more likely to be confused with Rosanne Cash, for whom she’s sometimes a ringer, than Karen Carpenter. Her “Shooting Straight in the Dark” LP isn’t quite as nakedly confessional as Cash’s current “Interiors,” but it’s not much less vulnerable. To be thirtysomething and single-something is to recognize too many intimate details in her often melancholic, always strong writing.

Like Cash, again, Carpenter is destined to be remembered more for her songwriting than her performing, which is naturally limited by the downbeat nature of much of the material--though, toward set’s end, she put her acoustic guitar down and let the rather polite backup band carry her through such stomps as NRBQ’s sprightly rocker “If I Don’t Have You” and her own two-stepper “How Do.”

Carpenter rarely comes off as a doormat in her pointed songs about losing in love. At times you might wish she could work up a little more bile, though. In one unrecorded song, she did: “Opening Act” was a hilarious diatribe directed at a country headliner, unnamed except for a two-syllable profanity. “I’m not goin’ bald so I don’t wear a hat,” she sang in her own defense; “I don’t wear tight jeans, I’m a little too fat.” Nope, this isn’t Karen.