In a way, saxist Tim Berne and pianist Ethan Iverson’s duo gig at the Stone on Friday began online a few days earlier. Last Monday, Iverson—best known for his work with The Bad Plus—posted a fascinating long-form interview with Berne on his blog, Do the Math, and the show’s intimate nature made it seem like a continuation of that wide-ranging chat. As in the Q&A, the contrast between the two musicians (pictured, as half of the collaborative quartet Buffalo Collison: from left, Berne, Iverson, cellist Hank Roberts and drummer Dave King) was striking in the live setting: If their rapport seemed uneasy at times, it also displayed a compelling tension.

In the intro to the interview, Iverson pegs Berne as “one of the saltiest, funniest men [he's] ever met.” The saxist’s deadpan banter at the Stone bore that out: “I can’t see, I can’t breathe, and this is the worst reed of all time,” Berne griped wryly after a particularly intense piece. Iverson, on the other hand, seemed happy to play the diligent straight man, as he had in the conversation.

But the pianist’s musical demeanor was anything but rigid. Whereas keyboardist Craig Taborn—who has worked often with Berne in recent years—tends to dedicate himself wholeheartedly to the saxist’s patented angular vamps, resulting in a remarkable sort of mind meld, Iverson takes a far more impressionistic approach. At the Stone he locked in tightly with Berne during the composed material (including several new works by both players), but once the written passages were out of the way, he favored oblique ruminations. During one piece, Iverson obsessed over a few high-register notes, striking them in slow, staggered succession. At other points, he offered enigmatic accompaniment by slamming the piano bench against the floor or teasing the instrument’s inner strings with his palm.

Lacking the strong rhythmic thrust of many other Berne projects, the duo sometimes seemed diffuse. But it was nevertheless fascinating to hear the saxist’s piquant lines set against such an abstract backdrop. (In that sense, the gig seemed a lot closer in tone to Theoretically, Berne’s 1983 matchup with guitarist Bill Frisell, than any of the horn man’s other contemporary work.) During the final piece, a medley culminating in a free-form ballad, the two players seemed to finally agree on a common ground: Their interplay felt urgently passionate yet open-ended, just like an intimate dialogue between friends.