For the last two years, pianist Ethan Iverson has been at the center of what looks, in hindsight, like a serious creative whirlwind. He re-conceptualized Stravinsky's ballet The Rite Of Spring in its entirety (!) for his trio The Bad Plus, and then, for good measure, recorded an album of all-original Bad Plus music (Inevitable Western). He recorded two crisply swinging trio albums with the drummer and jazz elder Albert "Tootie" Heath. He anchored the acclaimed quartet led by drummer Billy Hart (the group's 2014 release One Is The Other turned up on many best-of lists), and was part of another multi-generation group with pioneering saxophonist Lee Konitz. All while writing Do The Math, one of the most lucid, carefully reasoned blogs on contemporary music.

The work ethic is impressive, and arguably unique. But what makes Iverson extraordinary is the focused way he's managed these endeavors: He understands that each project has its own demands, aspirations and intended audience. He keeps things separate, drawing clear distinctions between his brainier compositional forays and his more reverential, sometimes scholarly investigations of jazz tradition. He does his serious innovating alongside bassist Reid Anderson and drummer Dave King in The Bad Plus, then gets his jazz on with the hot shots and legends who understand all his zany references and inside jokes.

This career strategy is tested on The Bad Plus Joshua Redman, a roaring and beautiful summit meeting that has no precedent in Iverson's discography. The first thing to know about it: Though Redman is among the most accomplished living practitioners of the jazz tenor saxophone, and can be counted on to shred on demand in a small group context, this is not a jazz date.

Instead, it's a series of knotty, deeply challenging compositions that explore (and usually exhaust) groove frontiers far from the spang-a-lang swing and the businessman's bounce. The rhythmic language here derives from rock and contemporary music, as well as the open, beautifully textural questing associated with the European avant-garde and certain strains of electronic music. The result: pulses that have an undeniable future-forward energy running through them. There's a spry, Aaron Copland-esque fantasy on rural Americana ("County Seat") and a haunting through-composed piece called "Beauty Has It Hard" that sounds, at times, as if Iverson has four hands going on the keyboard. And there's a wistful elegy ("The Mending") that distantly echoes Satie's piano music, as well as a filmic processional ("As This Moment Slips Away") that suggests what Band On The Run might have sounded like if Paul McCartney and Wings replaced the happy triads with dissonant chord clusters in 7/4 time.

So there's a lot of the trademark Bad Plus wonkery going on here; even the pieces built on straight-up rock-style backbeats tend to lurch away from predictability, with fitful odd-meter detours and sudden moments of explosive group upheaval. Several of the most engaging compositions share an unusual trait: After three or more minutes exploring one idea, they pivot into a second, related but contrasting mood that serves as another platform for improvisation or further compositional elaboration.

You have to do quite a bit of counting to apprehend all the stuff going on inside these tunes. But happily, it's also possible to enjoy this music without that work, largely because the settings play to Redman's strengths. Where Iverson is a calculating improvisor prone to rattling off lines that call attention to the cleverness of the writing, Redman shares more heart and lyricism, and this cultivates deeper group communication. He can handle all the tricky switchbacks embedded in the music — his own group, James Farm, aspires to similar meta jamming — but never allows the structures to dictate too much about his own inventions. He engages the trio with short taunts and jabbing lines, and then, over time, shapes them into longer sweeping arcs that sometimes exude a heroic spirit. The ideas are impressive by themselves, but become more powerful as Redman and the rhythm section go about developing them, especially in two older tunes known to Bad Plus fans: "Dirty Blonde" and "Silence Is The Question." All involved utilize call-and-response and other familiar jazz techniques, and there are "solos" in a conventional jazz sense, but what emerges is a zillion miles from summit-meeting jazz.

That's the real triumph of The Bad Plus Joshua Redman: It exhibits genuinely fresh thinking. Though the music is at times overwritten, and as a result can occasionally register as a dizzying brainiac barrage of information, each of these compositions thrives in provocative non-jazz settings for spontaneous exploration. And, like all steps forward, this one isn't entirely radical: It draws on a range of old ideas (as old as Chopin nocturnes and '60s rock) as fuel for a journey into the murky, terrifying, thrilling unknown.

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