Over 17 previous albums, the Necks have explored as many different kinds of space and texture the piano trio format (occasionally with electronics) would seemingly allow for. But Australia's longstanding avant-ambient jazz unit, while having an instantly identifiable sound, has never made the same record twice -- even though they typically employ a single, set-length track in doing so. Unlike their Northern Spy debut, 2013's airy, gentle, and drifting Open, Vertigo is a dark, brooding, sometimes dissonant -- and occasionally explosive -- outing. The 43-minute work is informally split into movement-like halves, though its sense of fluidity is constant, no matter what arises in the proceedings -- and there is plenty. Vertigo's guidepost is a single drone that runs throughout, allowing the musicians a centering device for their various rounds of improvisation and interplay. In the opening minutes, pianist Chris Abrahams improvises with busy lines in the middle and upper registers, answered by drummer Tony Buck as bassist Lloyd Swanton plays a low-end arco. Buck erupts occasionally with clattering cymbals, tom-toms, and the wood on his kit. Abrahams introduces an elliptical melody about ten minutes in via his left hand, while his right continues its series of flourishes. A synth slips in, or make that two, pushing against that intimate display of notes and tones as Swanton begins to pulse a single string with a snarl and Buck frenetically employs a host of percussion instruments adding drama. Elements of ambient noise, the plucking on the inner strings of the piano, and a single repetitively played high key push against the drone, which asserts dominance again before the piece resists, moment by moment, and then almost disintegrates. The second half begins with a sparse, ghostly Rhodes piano, offering single lines and spacy chords. Flits of electronic noise and a shimmering ride cymbal add mystery before the acoustic piano returns. The trio commences a dialogue without exchange -- all members speak at once. No one fights for the center, but all speak from different tonal terrains. When Buck enters with a squalling, feedbacking electric guitar answered by his own thudding tom-toms and Swanton's bass throb, Abrahams can only answer with aggressive synth washes adding to the din. And just as the work ratchets toward an intensity that might break it apart, bowed electric guitar, bass, and that drone emerge to re-center the piece with an uneasy sense of solace. Buck's drums reinstate their clattering force and the others answer by pushing back with circular percussive sounds on their own instruments. Vertigo is more expansive than Open -- even with its humid, uneasy sense of musical claustrophobia. It's no less engaging for its dissonance and tension. This is possible because the Necks understand how to instinctively balance sonic seduction with limitless exploration. ~ Thom Jurek, Rovi