Stunning, spatially bewildering album of steel drum experiments from The Knife’s Olof Dreijer aka legend Oni Ayhun featuring his old pal Mount Sims, who together evoke the spirits of Confield’s ball-bearing Gamelan, Steve Reich’s Electric Counterpoint and Mark Fell's microtonal metallophone recordings - to mesmerising effect.

When Dreijer and Sims were approached a decade ago by the Special Friends of the Earth organisation to work on music with a steelpan from Trinidadian legend Ellie Mannette, they were determined to approach the instrument with sensitivity in order to avoid awkward fetishisation, highlighting the drum's characteristic timbre rather than its expected application.

The duo spent years working with different techniques - playing the pan using droplets of water and ball bearings, for example, until they'd developed a way of bringing its softer, more unfamiliar textures to the surface. Just as Helge Sten created rare magic from an array of Harry Partch's custom-made instruments on last year's 'Sow Your Gold...', Dreijer and Sims dissolve familiar sounds into a bubbling pool of rich, queered harmonies and unstable rhythms.

Opening track 'Liten Karin' is probably the duo's most radical statement, a reinterpretation of a Medieval Swedish folk song that features Sims on vocals, singing over a patter of metal pans in slightly broken Swedish. Working with a Trinidadian instrument but looking critically rather than resting on romanticised aesthetics, they arrive on a sound that's mournful but not self-indulgently so, bringing out fragile beauty not restricted by Western temperament.

From here the music only gets more pointed and involving: the lengthy 'Hybrid Fruit' picks up on the loose thread of 20th century minimalism (think Steve Reich or Midori Takada) using repetition to accent the drum's ornate mutability. When things appear to evolve into techno-warped arpeggios, it takes a minute to realise it's not synths we're hearing but processed metallophone scrapes, like some organic approximation of the Berlin school's psychedelic cosmic electronics.

But it's when Sims and Dreijer veer off course that things go fully transcendent; on 'A Vessel of Clay', they reduce the sound of the steel drum to an icy crackle, letting bouncing ball bearings set a loose pace. It's not a million miles from Mark Fell's collaboration with Portugal's Drumming Grupo de Percussão 'Intra', fracturing percussion into glittering mosaics that reflect technology without being controlled by it.

The album peaks with 'Across This Mud', a noisy electro-acoustic workout that closes 'Souvenir' in fittingly dissonant style. The first track Dreijer and Sims wrote for the album, it's a fanged exercise that satisfyingly explodes into ear-crippling distortion. One thing's for certain - it ain't calypso.

One of the year’s most quietly mesmerising albums.