In Newsom’s hands, the harp becomes ultra cool

When was the last time you saw high school and college kids outside a rock club begging for tickets ... to a solo harp concert? That was the scene Thursday at the Troubadour for the sold-out appearance of Joanna Newsom.

If that image leaves you scratching your head, the situation inside wouldn’t have helped much, as Newsom looked as if she’d just hitchhiked in from the Elfin lands.

And then there was her singing, with the voice of a pixie. Or a cat. Or a pixie cat.

The Bay Area-based musician is certainly an acquired taste. But she’s also the personification of the anything-goes expansiveness of the indie music renaissance, as attested to by the rapt attention the crowd paid her.

Falling somewhere between the Celtic hippie mysticism of ‘60s English outfit the Incredible String Band and the idiosyncratic wonder of Bjork, Newsom proved a distinctive presence even in the current psych-folk revival revolving around her friend Devendra Banhart. For anyone getting past the peculiarities, there are great rewards.

Her playing favored Celtic-rooted pointillist plucking (none of those lush, swirling classical runs), providing a perfectly twinkling setting for her quirky, capital-R Romantic mix of rustic and modern imagery.

Pieces from her 2004 debut album “The Milk-Eyed Mender” (released by Chicago’s ultra-hip Drag City label) were all the more charming live, but two new extended songs stood out for the sophistication of both musical and lyrical development, reminiscent of former Incredible String Band member Robin Williamson’s solo work.

Perhaps the defining moment, though, was when a baby in the crowd cried and Newsom paused to admire and coo. Yes, a baby.

When was the last time you heard that in a rock club ... and it didn’t seem out of place?