Improvisation is a rewarding, creative skill. It’s also a learned skill, and like any skill, it improves with practice. Few major classical performers stray into this territory, so it’s commendable that star violinist Hilary Hahn has taken the plunge into playing without printed music, collaborating with a musician from outside the classical music bubble — the German pianist Hauschka — on the new CD “Silfra” and on an attendant album tour that came to the Birchmere on Monday night.

But listening to their performance was like watching an artist doodle on a notepad. Some of the doodles are mundane, others are promising and none of them are quite on the level of a finished product.

Technically, one supposes, “improvisation” means making something up as you go along, but one awaits some kind of adroitness or direction in the process. Hahn, new to improvising, tended to cling to one note or pattern like a baby keeping herself upright by holding on to the sofa. Only occasionally, in a couple of solos, did she dare to let go enough to take a few steps into melody, generally sounding vaguely Celtic: New Age meets Riverdance.

Hauschka, playing the prepared piano — that is, a piano with objects inserted between, upon and under the strings to create unexpected timbres, resonances and pitches — did most of the heavy lifting in terms of making things happen: changing, for instance, the mood of one aggressive improvisation with a softer middle section. But generally, not much did happen: The pieces tended to open with what sounded like introductory material and then stay there, as if not sure where to go next, until they died away.

On the album, produced, the whole thing sounded more purposeful; here, it often seemed rudimentary.

Musicians Hilary Hahn and Hauschka. (Courtesy of The Birchmere)

The presentation also left something to be desired. The audience got an unbroken hour and a half of music, plopped down in front of it with the friendly mien of a dog offering a freshly caught specimen to its owner and waiting for praise. An advantage of playing in a club is that it provides musicians a chance to talk to the audience, and Hahn and Hauschka offered a few bantering remarks — “It smells like dinner!” Hahn said as she took the stage and joked about trying her hand at singing — but these remarks didn’t offer any insight into what the artists were aiming for or thought they were doing. They didn’t even explain the prepared piano, so at the end of the show, when Hauschka began to strip the instrument of its various objects, returning it to its original timbre, a lot of audience members began laughing, as if they thought the man pulling things out of the piano was a sight gag.

Doodling is eminently creative work, freeing the brain and often leading to wonderful ideas. But it’s a mistake to confuse this window into the process with a finished result; and it’s a mistake to think that doodling alone will lead you to worthwhile expression. There are techniques to learn, and ideas to be processed, that help any artist hone what she wants to say. Those techniques, it seems, still lie in Hahn’s future. I hope she chooses to explore them, and I admire her for having the guts to go out on a limb in public, but I don’t feel the need to hear her improvise again for a good long time.