The Necks started in 1987 as an experiment conducted in private, not intended for public exposure. That changed as soon as the three musicians realised how well their collectively improvised music was working, and with Travel, their 19th studio album, they stay true to the process that has served them so effectively. Unchanging in its essence but never standing still, it has carried its members, two Australians and a New Zealander, from their late twenties to their early sixties on a steadily unfurling wave of creativity, as richly nourishing to their devoted audience as to themselves.

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Consciously or not, there’s a lot of Zen in the way The Necks go about making music, most particularly in the way habits are used as a way of breaking habits. In the improvisations that make up their live performances, one member of the group is designated to begin before the others join in at a time and in a manner of their choosing. To construct Travel, The Necks created four shorter live-in-the-studio improvisations and subjected them to the sort of post-production techniques used on many of its predecessors, overdubbing extra layers of sonic texture, most frequently the pianist Chris Abrahams’ Hammond organ and the guitars of the drummer Tony Buck. Through these methods they dramatise each piece, enhancing the quality so cherished by their admirers: a slow-burn narrative arc that can lead anywhere, but never on a whim.

The length of the pieces was determined by the decision to make each of the four to fit a side of a 12-inch vinyl LP, meaning that Travel exists as a double album as well as an 80-minute single CD. This repeats the format used on Unfold, released in 2017 on the Ideologic Organ label. Pieces of a similar length were also created for the three-track CDs Chemist (2009) and Three (2020) and the two-track Mindset (2011), but the results here feel more fully realised, richer and deeper.

The first of the four pieces, “Signal”, opens with a supple two-bar riff from Lloyd Swanton’s warm-toned double bass, joined by Chris Abrahams’ single-note piano lines and by Tony Buck’s susurrating cymbals and ticking rimshots. The piano is replaced after several minutes by a watery organ figure, joined by a pair of Buck’s overdubbed guitars playing ska-type double-time backbeat chords on either side of the stereo picture, slightly out of sync. As the organ fades, the bass riff is subjected to small variations and the piano returns to resume its increasingly elaborate meditations, a prod in the bass end of the keyboard occasionally reinforcing Swanton’s constant repetition of the piece’s root note. Then the organ arrives from another direction and in a different guise, gently growling a new riff laid asymmetrically across the basic two-bar pattern, thickening the texture supporting the piano. Buck’s drumming stays in place throughout the 20 minutes, churning busily but discreetly under the groove in such a way as to give the impression that he’s steadily speeding it up, which in fact he is, since he and his colleagues have smoothly accelerated from 110 to 120 beats per minute over the course of the piece. By the end the bass has reduced itself to silence, the chack-chack of the ska-style guitars maintains the pulse, the piano repeats a two-note treble phrase and the cymbals shimmer to a halt in a distant heat-haze.

“Forming” is defined by the Moorish accent of Abrahams’ piano phrases, spreading over the tempo-free textures of Buck’s tom-toms, Swanton’s alternation of sonorous lower-register bowed phrases and the high strumming of a single string, and organ chords discreetly hovering in the background. While Abrahams floats above it, Swanton grounds the piece, working furiously to create an almost orchestral effect before retreating as Buck looms out of the mist with a wild pounding that is beautifully held back in the mix. While there’s no explicit rhythm, there is now an extremely powerful flow over which Abrahams can use delay within his phrasing to create the illusion of slowing the time down. The incantatory effect is enhanced by Swanton, who returns with bow in hand, sawing furiously, amplifying the turbulence under the serene piano. For a moment you’re tempted to think that this is where McCoy Tyner, Jimmy Garrison and Elvin Jones might have gone, had the classic John Coltrane Quartet stayed together.

Swanton’s bowed bass harmonics, sounding surprisingly like the breathy tone of a shakuhachi, open “Imprinting” against the sort of shuffling noises Buck often makes by manipulating strands of small metal objects across the head of his snare drum with one hand while the other is pattering across his tom-toms, working up a rhythm that is regular but not subdivided by bar lines or cadences. As the organ seeps into the backdrop, soft-toned single-note phrases emerge from what sounds like some non-binary instrument sharing the precise articulation of a piano and the note-bends of an electric guitar: most likely some processed version of the former, whose true sound is occasionally allowed to emerge. Essentially, “Imprinting” is a gently relentless one-chord jam on the blues in E minor.

There’s a lot of blues, too, in the final track, or LP side. The Necks’ history includes a number of concerts in churches, using on-site pipe organs, and the majestic tones of such an instrument provide the opening fanfare of “Bloodstream”, joined by surprising gospel phrases from the piano, with Abrahams channelling the ’60s soul-funk style of such jazz pianists as Bobby Timmons and Les McCann. It’s a reminder that the combination of organ and piano was a staple of black church music before finding its way into rock via Procol Harum (Matthew Fisher and Gary Brooker) and The Band (Garth Hudson and Richard Manuel); this is an extended exploration of its possibilities, the piano growing more florid and the organ more celestial. Swanton’s bass keeps up a thrumming and droning background while Buck adds rolling thunderclouds and occasional flashes of lightning to another piece that never falls into a regular metre.

“By the time we’re well into a piece, it’s really hard to imagine even how it got there from where it started,” Buck said to me many years ago, while Abrahams remarked on how their music brought “an understanding that things can find a way of becoming other things while you’re performing”. If Travel perhaps lacks the sense of profound revelation that can result from total immersion in The Necks’ hour-long epics, whether in person or in their studio creations, the relative brevity of these four pieces permits an easier engagement with their approach, with the way these three remarkable musicians, while working at their own pace on every level, continue to explore a sound-world and a collective methodology entirely of their own conception.

Is it among their best? It’s another Necks album, meaning another 80 minutes of what, when considering the 35 years of their career to date, can seem like gazing out of the window on a marathon flight crossing continents, each vista – deserts, mountain ranges, forests, seas – imperceptibly or abruptly giving way to the next. Sand, rocks, trees, water: all are the same and yet never the same twice. The music that began in 1987 continues on its unbroken path, always familiar but always different. Travel is well named.