After some guerilla-style social media marketing, the Oxfordshire band’s ninth album was released online on Sunday evening (vinyl and CD versions won’t appear until mid-June).

The opening salvo, Burn The Witch, whets the appetite for a strident, edgily melancholic set, all programmed drums, percussion and strings running the gamut from symphonic, emotive sweeps to staccato strikes.

Frontman Thom Yorke wraps his distinctively fragile, high-register vocals around them, singing disconcerting and semi-cogent warnings of “a low-flying panic attack”.

But it turns out to be the most outre song of a mellow, intricate album that belies its rich sonic detail and gritty, unnerving lyricism.

Decks Dark shimmers in a hazy half-light – evoking visions of the titular pool, perhaps hidden in a network of caves - and lays heavenly choral voices and languorous guitar over chiming, gently gurgling percussion and samples.

Desert Island Disk comforts with finger-picked, Eastern-flavoured semi-acoustic guitar and pensive cymbal, while the oscillating strings of Tinker Tailor and choppy percussion of Identikit all hint at their long, considered gestations.

Like Japan’s Shinkansen trains, Ful Stop (sic) glides along as Yorke’s vocals stretch toward the horizon, all the while drum and percussion rattling quietly along beneath.

And Daydreaming centres on solo, plangent piano refrains that lilt in a gently fizzing, gossamer-electro soundscape recalling Nils Frahm. Familiar elements from other artists emerge, too – John Martyn, Pink Floyd, Nick Drake, Serge Gainsbourg and even their own late-’90s selves - but they’re warped into fresh and compelling incarnations.

Lastly, True Love Waits, a song penned in the mid-’90s, finally gets a studio version, bookending the album with a seemingly heartbroken vocal quivering over a shimmering pool of chiming piano.

An album of humbling, glorious melancholy and a surprising return to form, Radiohead have pulled off an accessible record of dense and detailed arrangements that signal true craftsmanship at work.

Rating: 4/5 stars