Let’s presume it’s not too obvious a question at this late stage in the game—a century after those original New Orleans marching bands decided to swing round corners on the way to the cemetery with a syncopated spring in their step; almost as long since King Oliver taught Satchmo how to blow his soul out the end of his horn and say what he damn well felt like saying—to ask exactly what is the relationship between improvisation and jazz?

At one end of the spectrum, there’s the jazz Neo-Con brigade, staunchly guarding the gates to the Lincoln Centre, preserving history with meticulous heads and just enough room in the chorus to cut out a neat little lick, enough to satisfy anyone dumb or persistent enough to ask just where in the hell their fire went. Or, to take things to the other extreme, witness the mind-scraping weirdness that’s become the legacy of free improvisation since the New Thing became the Old Thing, with Ayler dead, Sun Ra back on Saturn, and pioneers like AMM abandoning the blues altogether to lay down low, shimmering vistas of electronic, cosmic ambience. You have to ask yourself: is there no middle ground?

It’s a question pianist Greg Burk tackles head on in his new release, Nothing, Knowing. Supported by two veterans on stellar form, Steve Swallow on electric bass and drummer Bob Moses, Burk navigates structured compositions, free improvisations, and, perhaps most germane to the concerns of this collection, pieces that meander from one extreme to the other, taking structure as the springboard for freedom and viewing freedom as the gateway to form. The disc’s opener, “Old Souls” is a case in point, moving from a delicate, dawn-like refrain to a more frenetic freedom, with Burk’s questing right-hand hurried along by rapid-fire, skittering percussion and grounded by solid, spacious bass figures, before sliding gracefully back into a reprise of the theme and ending with the satisfying inevitability of an intended destination. It’s a beautiful demonstration of how, in the right hands, self-imposed limitations can make real improvisation more challenging and satisfying than complete freedom.

In terms of pure, spontaneous invention, the album’s centrepiece is the 19-minute improvisation “Truth Be Told”—perhaps the CD’s most compelling showcase of Burk’s quirkily lyrical technique, one that owes more to his former teacher Paul Bley than it does to other more aggressively percussive and overtly radical pioneers like Cecil Taylor. Make no mistake, though, this tune just flies by. Almost from the outset, it launches into an up-tempo, free-jazz maelstrom, with Moses’s frenetic drums urging the trio forward, until a peaceful plateau of calm is reached. Once the trio is regrouped, up comes a clattering, insectoid drum solo bubbling to the surface, augmented with pizzicato dabs of bass and finally swirling piano figures that lead back into an energised, churning vortex, with Burk providing insistent, quizzical left-hand chords and a torrent of nimble melodic ideas. Waves of activity swell and subside, intensity rising and falling like birth pangs, until finally the tumult descends into a bluesy come-down, with Swallow’s bass walking authoritatively over fizzing drums and the piano playing the theme to the home stretch.

Some of the other, shorter numbers offer a glimpse of Burk’s compositional eclecticism. “Look to the Neutrino” begins with roiling, swelling clouds of improv before coalescing into an almost prog-rock marching figure with martial chords and Swallow’s electric bass high up in the mix, while “Borneo Dreaming” conjures up an unmistakable exoticism anchored by Swallow’s Nubian-sounding bassline—not unlike Sun Ra’s “Angels and Demons at Play”—hounded by chaotic, jungle percussion, while Burk searches inside the Steinway’s guts, looking for a lost civilisation among the strings.

On “Operetta”, we find the intellectual crux of the CD in deceptively simple form, as it starts off as a breezy, upbeat bossa nova before Moses’s inventive, rubato rhythm begins to pull it away from its moorings, steering it clear of the cheesy lounge-area it was headed for. Similarly, “Big Bird” is the closest this group comes to straight-ahead post-bop, once again subverted and dragged purposefully out of the mainstream by Moses’s relentlessly unruly drum patterns. It’s this tension between rigour and rebellion—as the bass and piano skirt around the central theme while shadowing the drums way out in the left-field—that encapsulates this set’s comment on the role of improvisation in contemporary jazz and how sometimes it’s only limitation that makes freedom worthwhile.

Now, take a glass of water. Hold it up to the light. See how the liquid fills the glass: pure potential, amorphous, colourless, utterly adaptable, yet defined by the rigid glass walls around it. Now pour that water out onto the ground, see how it runs away, uncontrolled. Ain’t quite so beautiful any more is it?