In the wild world of underground instrumental music, Marco Benevento is a newcomer as a leader, but he's no stranger to the scene. The thirty-year old Berklee School of Music grad studied jazz piano under Joanne Brackeen, Kenny Werner and Brad Mehldau and set up shop in New York City seven years ago cultivating credibility gigging there.

Eventually, he settled into a duo format with high school buddy drummer Joe Russo and the two cut four albums together. In 2006, they formed part of phormer Phish leader Trey Anastasio's tour band. The following year, Benevento finally debuted as a solo artist with his sprawling, three-CD live document Live At Tonic.

Which brings us to the present. This month, with Invisible Baby, Benevento debuts in the more customary sense: a studio album with all selections written by Benevento himself.

None of what has been recounted thus far says much about what kind of music Benevento plays, at least for the album being discussed, here. That's the tough part about writing this review.

Benevento's signature sound, at least on Invisible Baby, is familiar, yet nearly impossible to pin down. Since it's all instrumental with some quality chops being displayed, there's the temptation to call it "jazz," but that doesn't do his music any proper justice. I first listened to this record with a jazz ear and found it lacking. You can find signs of Mehldau's strong melodic sense, for instance, but little of his cerebral improvising. The songs stubbornly don't swing. The chords played usually aren't jazz chords.

Taken as a form of experimental rock, though, and you've got a creative, imaginative brew of ideas. Even coherent.

Benevento is fond of conjuring up an ostinato, adorning it with some electronic effects laid upon a bedrock of piano, then going several rounds with it before switching over to a different repeating figure. A key to making it succeed is that these vintage-sounding electronics, which he calls "circuit bent toys" — a homemade array of effects pedals — provide a sideshow to the tunes without taking center stage away from his substantial piano.

The other primary ingredient is that these songs are rock in spirit, tone and rhythm. Some people would call all this post-rock.